Glossary

Denoted as ε, it is a critical parameter for determining friction factors in turbulent flow.

It provides a measure of the microscopic irregularities on the internal surface of a pipe, expressed in units of length (such as mm or inches). It represents the actual physical height of surface irregularities that increase friction and turbulence in fluid flow.

Mathematical relationships that describe how pump performance parameters (flow rate, head, and power) change with variations in impeller diameter or rotational speed. FluidFlow automatically applies these laws when modeling changes in pump speed or impeller diameter.

Formula:

Q₂/Q₁ = (N₂/N₁) × (D₂/D₁)

H₂/H₁ = (N₂/N₁)² × (D₂/D₁)²

P₂/P₁ = (N₂/N₁)³ × (D₂/D₁)³

Where:

Application: Used in FluidFlow to optimize pump performance by adjusting speed or impeller size to match system requirements and optimize energy consumption.

Atmospheric pressure and temperature where the system is exposed to. It serves as a reference in gauge pressure, boundary conditions and several heat transfer model calculations.

FluidFlow has the feature to account for the effects of system grade elevation with atmospheric pressure through the Global settings tab of the Calculation Options dialog box.

American National Standard for Rotodynamic Pumps – Guidelines for Effects of Liquid Viscosity on Performance.

This guideline can be applied in calculations by ticking the checkbox in the calculation options dialog box under the global settings tab. It would automatically adjust water-based centrifugal pump performance curves when pumping Newtonian liquids with kinematic viscosities of 4.3 cSt or higher to account for viscosity effects.

Present in the components below, this software feature is used for determining equipment characteristics needed to attain a defined specification:

• Pump
• Compressor
• Control Valves (Flow, pressure reducer / sustainer / pressure differential)
• Orifice
• Pressure Relief Valves
• Venturi
• Nozzle

Reverse calculation feature in FluidFlow that determines the required input data from a defined calculation result.

Pressure downstream of an in-line pipe equipment such as relief valve or control device. This parameter is applied as guide when sizing or evaluating equipment performance for capacity, flashing and unwanted two-phase flow at the discharge.

Fitting used to join conduits to redirect orientation at a certain angle.

The change in flow direction cause additional pressure losses.

Duty point on the centrifugal pump performance curve where pump efficiency and reliability is at their maximum and thus the most favored operating point.

In pump selection and evaluation, performance within 130% of BEP is typically considered acceptable, while attaining 90% – 110% of BEP is considered best practice.

Comprehensive list of all components, pipes, and equipment in a FluidFlow model, automatically generated for procurement and cost estimation.

Non-Newtonian fluid that demonstrates a linear shear rate vs. shear stress relationship or a constant viscosity upon exceeding the yield stress.

Mechanical devices that transport fluid from source to destination by increasing fluid pressure. In FluidFlow, a booster can either be a pump, compressor, blower or fan.

Start and end nodes of a FluidFlow hydraulic model.

The node where the model begins or from which fluid information is sourced for calculations is known as the “inlet boundary,” while the endpoint is commonly referred to as the “outlet boundary.”

FluidFlow has a wide selection of boundary nodes available:

• Known Flow
• Known Pressure
• Reservoir
• Open Pipe
• Sprinkler

Angle at which junctions connect pipes with each other. This information is used as one of the basis in calculation junction pressure loss.

Heat transfer calculation method in FluidFlow for underground piping systems accounts for the heat transfer characteristics of:

• Soil
• Buried Depth
• Soil Temperature
• Pipe Coating (Optional)
• Insulator (Optional)
• Backfill (Optional)

Non-reclosing pressure relief device designed to rupture at a predetermined pressure, providing overpressure protection by relieving dangerous pressure or vacuum buildup.

In FluidFlow, these devices can be modelled by setting the role of the Relief Valve node as either:

• Bursting Disk
• Safety Valve and Bursting Disk

When modelling as bursting disk, users have the option of defining the certified resistance coefficient “Kr”.

Friction losses from bursting disks are calculating using resistance to flow method.

Dialog box that appears by pressing F2 or via Options menu → Calculations.

It configures convergence settings, general approach and assumptions applied for performing liquid, gas, two-phase, slurry or pulp and paper stock calculation.

Non-Newtonian fluid that demonstrates a unique linear shear rate vs. shear stress relationship upon exceeding the yield stress observable in fluids similar to blood, printing inks and chocolate.

Phenomena where the local liquid pressure falls below its vapor pressure, resulting to formation of bubbles that collapses and cause a mechanically damaging energy release on exposed surfaces.

Pump type that create work to increase fluid pressure by using the rotational energy of its impeller.

The impeller’s rotation introduces kinetic energy to the liquid, causing it to move outward due to centrifugal force. As the fluid moves outward, its velocity decreases, converting kinetic energy into pressure energy at the discharge.

Basic checkpoints for evaluating centrifugal pump performance:

• Achieving duty point
• Proximity to best efficiency point (BEP)
• Adequacy of NPSHA versus NPSHR

Drop in pump performance caused by the additional pressure loss exerted by the solids in the slurry or non-Newtonian viscosity effects.

In the centrifugal pump node, any of these five (5) solids derating methods can be applied:

• Fixed Reduction Ratio
• King
• HI Guidelines
• ANSI Monosize
• GIW 4CM

Centrifugal pump performance curves are provided by manufacturers to present details on the resulting differential head, efficiency, power or required NPSHR as flow, impeller size or speed is varied for a given pump model.

This information can be installed in hydraulic models upon storage in the booster database and when the automatic sizing feature is OFF.

Application of centrifugal pump performance curve in models enable determination of actual pump performance against hydraulic performance criteria to determine its suitability for the intended service.

Valve used to protect piping systems by preventing the reversal of flow and hence are unidirectional.

Typical applications are on the discharge side of a booster where backflow could damage the internals of the equipment and cause an unnecessary shutdown of the system.

Some types also protect pumps from running dry, such as foot-operated check valves that trap liquids in pump suction pipes for lift stations.

These check valve types can be modelled in FluidFlow:

• Swing Check Valve
• Tilting Disk Check Valve
• Piston Operated Check Valve
• Spring Loaded Check Valve
• Foot Operated Check Valve

In FluidFlow, it refers to the systematic categorization of pipes based on their specification: schedule, inside and outside diameter.

Individual element in a FluidFlow model representing physical equipment such as pumps, valves, pipes, or fittings.

Graphical display of component hydraulic characteristics in a FluidFlow model accessible through the data palette.

Graphical display of hydraulic characteristics exhibited by two or more components in a hydraulic model in any of the following form:

• Parallel and Series Pumping
• EGL Plot
• HGL Plot
• Elevation Plot

Composite charts can be created through the Tools menu.

Connection rules are basic philosophies in FluidFlow used as guide when linking one pipe to another.

In summary, the rules are:

Pipe always end in nodes
Pipes must always end at a node connection. Hence, a pipe with no other connection would always terminate with an open pipe end.
Deleting a node where a pipe is connected will also delete the pipe.

Smart junction placement
Pipe junctions adjust automatically depending on the number of connecting pipes up to a maximum of four. Two connecting pipes generate an elbow or a bend; three, a tee or a wye; and four connections, a cross.
Default junctions can accommodate a maximum of four (4) pipe connections using a cross.

Unlimited connection
A connector can accommodate over four (4) connections.

No invalid connections
Invalid connections are automatically prevented. For instance, users cannot connect a third pipe connection to a pump or a fifth connection to a cross junction.

Unsolvable connections
Models containing nodes with missing pipe connections are unsolvable.

Unlimited boundary connection
The Reservoir node is the only boundary with fluid and temperature definition capable of accommodating more than one (1) pipe connection.

Pipe Splitting
Inserting a pipe to pipe connection forces its original input length to be defined according to the flowsheet option settings. It can either be split into two equal lengths or duplicate the pipe length data.

Pipe Merging
Deleting a node between two pipe will cause a length definition equal to the sum of the two pipe lengths.
When two pipes with different sizes are connected with each other, the larger pipe size will be applied as input data.

Connectors are junction types that do not generate pressure losses but introduce pipe inlet and exit losses.

It is typically used to model junctions requiring more than four (4) pipe connections.

Controllers in FluidFlow is a collective term for nodes that is used to model different devices for controlling flow, pressure or temperature at a given point in a fluid transport system.

A controller node can be any of the following:

• Self Acting Pressure Sustainer
• Self Acting Pressure Reducer
• Self Acting Differential Pressure Controller
• Pressure Control Valve
• Flow Control Valve
• Gas Regulator

Except for gas regulators, controller nodes can be autosized to determine preliminary valve Cv values. They can also simulate system performance using control valve manufacturer data.

The point during iteration when calculated variables such as flow, pressure, or temperature no longer change beyond defined tolerance limits.

In FluidFlow, correlations are empirical formulas that represent a relationship between two data and is used as a reference to determine a variable from another.

Calculation of the following variables in FluidFlow apply correlations:

• Newtonian friction loss
• Junction pressure loss
• Two-phase (liquid-gas) pressure loss
• Non-Newtonian friction loss
• Settling slurry horizontal friction loss
• Settling slurry vertical friction loss
• Settling slurry deposition velocity
• Inclined pipe settling slurry deposition velocity
• Pulp and Paper stock pressure loss
• Centrifugal pump derating

Cross junctions are junction types that do not generate pressure losses and cater four (4) pipe connections.

Valve characteristic that describes the amount of flow passing through the valve for every pressure drop generated. It is expressed in terms of US gallons per minute measured per 1 psi pressure drop at 60°F.

For control valves, FluidFlow calculates Cv using ANSI/ISA-75.01.01-2007 standards.

Also known as deposition limit velocity (Vs). Threshold flow velocity that describes the minimum velocity needed to prevent solids from forming a stationary bed for a particular solids concentration (Cvd).

This characteristic velocity is derived from the maximum deposition limit velocity (Vsm) using the Wilson 1986 model for relative solids volumetric concentration – Vs – Vsm relationship.

Formula:

Vₛ/Vₛₘ = 6.75Cᵣᵅ(1 − Cᵣᵅ)²                     Cᵣₘ ≤ 0.33
Vₛ/Vₛₘ = 6.75Cᵣ(1 − Cᵣ)²ᵝ[1 − (1 − Cᵣ)²ᵝ]      Cᵣₘ > 0.33

α = ln0.33333 / lnCᵣₘ
β = ln0.6667 / ln(1 − Cᵣₘ)
Cᵣₘ = 0.16D⁰·⁴ / dₘₘ⁰·⁸⁴[μₛ((Sₛ − S𝒻)/0.66S𝒻)]⁰·¹⁶⁵
Cᵣ = Cᵥd / Cᵥb

Where:

Fundamental formula used for calculating pressure loss due to friction in pipe flow.

The equation is expressed as:

ΔP = f × (L/D) × (ρV²/2)

Where:

User interface in FluidFlow typically located in the right side of the screen or accessed through the view menu.

This palette is used as one of the central feature for interacting with the objects found in the flowsheet. It is used to perform the following operations:

• See warning messages
• View results per component
• Access component charts
• Locate, select or multi-select components through the list tab

Organized collection of fluid properties, standard pipe dimensions, booster vendor information and component flow-pressure drop characteristics used in FluidFlow to simplify and reduce volume of data entry.

Mass of a substance per unit volume of space occupied.

Also known as maximum deposition limit velocity ($V_{sm}$). Threshold flow velocity that describes the minimum velocity needed to prevent solids from forming a stationary bed regardless of concentration.

FluidFlow calculates deposition velocity using any of these methods:

• As a function of particle size (Wilson 1997 Model)
• WASC generalized relationship (Wilson 1992 Model)
• VSCALC ( Multi-correlation involving Wilson – GIW, Thomas 1979, Thomas 2015 and Wilson 1992 Models)

Interactive window in FluidFlow used for entering component data, configuring calculation settings, units of measure, visible results, default input data, etc. accessible through any of these options:

• Menu Option
• Mouse Right Click within the flowsheet or data palette
• Function Keys

Difference in total head between two points in a hydraulic system.

It’s commonly used when referring to:

• Head added by the pump (differential head)
• Head loss across a component (pipe, valve, heat exchanger, etc.)

Modeling components that require flow direction definition—such as boosters, check valves, flow control valves, and tees—visually recognizable by a red dot marking at pipe connections.

Detailed heat transfer model applicable for pipe components capable of calculating and accounting for overall heat transfer coefficient of insulated pipes using the following information:

• Insulation thermal conductivity
• Insulation thickness
• Ambient temperature
• Local Wind speed
• Surface emissivity

Device used to supply mechanical energy to a booster (i.e. pump or compressor). Depending on requirements, it can be a motor, turbine or engine.

Pump efficiency achieved at the pump duty point.

Pump flow output for a given pump head developed.

Head difference between pump suction nozzle pressure and the liquid vapor pressure.

It is a pump suction system characteristic that influences pump selection and is required to be higher than the Duty NPSH Required.

Minimum head difference between pump suction nozzle pressure and the liquid vapor pressure needed by a certain pump model to avoid cavitation.

It is a unique pump characteristic specified by pump manufacturers and is greatly influenced by pump design and flow rate.

In pump selection, Duty NPSH Available should always be higher than Duty NPSH Required.

FluidFlow performs this comparison and generate warning messages accordingly.

Achievable flow and differential head of a certain pump model against the resulting system pressure drop.

In pump performance chart analysis, it is recognized as the intersection of the pump performance and system curves.

Power sent by the pump driver to the pump liquid at duty point.

Head developed by the pump at duty flow. See Differential Head.

Friction loss calculation method used by FluidFlow for compressible flow systems, originally developed by H.A. Duxbury for calculating high-speed gas flows in pressure relief lines.

Unlike conventional pressure drop calculations for compressible flow, this method incorporates real gas behavior when determining pressure loss between two points.

Pipe flow velocity that results in the minimum total cost of building and operating a particular piping system.

FluidFlow uses the Generaux equation to calculate economic velocity. This calculation requires not only process conditions, fluid properties, and pipe system details, but also considers installation costs, maintenance expenses, depreciation, energy costs, booster efficiency, and tax implications.

V = \frac{4}{\pi D^2} \cdot K^{1/(2.84)}
K = \frac{D^{(4.84+n)} \cdot nXE(1+F)[Z+(a+b)(1-\phi)]}{(1+\frac{0.794L_e’}{D})(0.000189YK\rho^{0.84}\mu^{0.16})[(1+M)(1-\phi)+\frac{ZM}{(a’+b’)}]}
M= (a^′+b^′)(E∙P)/((17.9 K∙Y) )
n= (Log C-Log X)/(Log D)

Where:

Ratio of the work or hydraulic power absorbed by a fluid to the input power supplied by the driver represented in percentage form. It provides a measure on the effectiveness of energy conversion from driver power source to mechanical energy into absorbed by the fluid during transport.

Acronym for “Energy Grade Line” developed as a composite chart in FluidFlow.

It is a graphical representation of the total head available to a fluid at a certain point in the flow path.

Distance at a certain point in a system measured vertically from a reference point.

Vertical distance differential between two points measured using the same reference point.

In FluidFlow, an “environment ” contains a range of default or user-defined settings for the items below which can be saved, shared and re-used as “set” for future modelling activities:

• Units of Measure
• Visible Component Properties
• Component Defaults

Equation that describes the relationship of pressure, temperature and volume of a given fluid in thermodynamic equilibrium.

In FluidFlow, EOS are applied for correlating variation of physical transport properties such as density, viscosity, specific heat and thermal conductivity against pressure and temperature during calculation.

Analysis feature in FluidFlow accessible from the tools menu used for evaluating pump or control valve performance under defined operating conditions.

Heat transfer modelling method that allow users to directly specify fluid temperature change across a component at a defined heat transfer direction.

This feature is available in all components except known flow, known pressure and reservoir nodes.

Heat transfer modelling method that allow users to directly specify heat transfer to a fluid across a component at a defined direction.

This feature is available in all components except known flow, known pressure and reservoir nodes.

General characteristic pattern of fluid movement within a pipe or channel characterized by Reynolds number.

The space allotted in FluidFlow for placing and connecting hydraulic model components.

A substance either in the form of liquid, gas or a combination of both that has no fixed shape and tends to flow in response to an applied force.

Term used to classify fluids in FluidFlow into any of these categories:

• Pure Newtonian Fluid
• Simple Newtonian Liquid
• Gas (No Phase Change)
• Non-Newtonian Liquid
• Petroleum Fraction

Dynamic property table that appears in the flowsheet upon hovering across a component.

It can be engaged through the Flowsheet setting toolbar using the “Show Flyby” button and can be customized through the Set Visibly Flyby properties dialog box accessible through any of the following:

• F6
• Mouse Right Click at Data Palette
• Options Menu under Environment ribbon

Component group in FluidFlow used to model flow versus pressure drop relationships that aren’t available through other components.

These nodes are typically used to represent specific piping system equipment not readily available in FluidFlow’s standard component library.

Input dropdown for pipe components that describes the flow cross-sectional area profile.

Pipe geometry options available are:

• Cylindrical
• Rectangular / Square
• Annular

When non-cylindrical options are selected, additional input fields appear to adequately define selected geometry.

Hazen – Williams Friction factory vary with pipe material and condition, an additional input field for pipes appears when this friction loss model is applied.

This table shows the Hazen-Williams coefficient (C) values for different pipe materials:

This friction loss model is applied to systems with liquid water or fluids having similar properties to water at 60°F, under turbulent flow conditions. It is particularly useful for modelling fire protection and closed-pipe irrigation systems.

∆ H= Factor∙L_e (100/C)^{1.85} Q^{1.85}/D^{4.8655}

Equipment that transfers heat between fluids, commonly installed in systems for space heating, refrigeration, air conditioning, power generation, chemical processing, petrochemical operations, petroleum refining, natural gas processing, and sewage treatment.

FluidFlow can model pressure drop across the following heat exchangers using Fixed Temperature Change and Fixed Heat Transfer Rate heat loss models:

• Shell and Tube Heat Exchanger
• Plate Heat Exchanger
• Jacketed Vessel (Process Side)
• Knock Out Pot

When modeling heat exchangers, each component accommodates only two pipe connections. Therefore, the hot and cold sides of heat exchangers must be modeled separately.

Analysis feature available in all components except known flow, known pressure and reservoir nodes used for simulating the effects of heat transfer in fluid transport using any of the following models:

• Fixed Temperature Change
• Fixed Heat Transfer
• Do Heat Loss Calculation
• Buried Pipe

Non-Newtonian fluid that follows a power law model upon exceeding the yield stress.

Depending on the flow behavior exponent, its viscosity may increase (thickening at n> 1) or decrease (thinning at n<1) as shear is introduced.

See Settling Slurry Horizontal Pipe Friction Loss Correlation.

Acronym for “Hydraulic Grade Line” developed as a composite chart in FluidFlow.

It is a graphical representation of the total head available to a fluid excluding kinetic energy or the velocity head at a certain point in the flow path.

Rotating component of a pump or compressor that features vanes or blades designed to increase fluid kinetic energy, consequently converted to pressure at the discharge point.

Adjustment method applied to settling slurry flow calculations in FluidFlow to account for pipe inclination effect on deposition limit velocity.

One of these two correction methods configurable in the Slurry calculation options can be applied:

• Wilson – Tse 1984 Chart
• Extended Wilson – Tse 1984 Chart

The procedures for correcting deposition velocity for pipe inclination are generally the same, except that the Extended Wilson-Tse 1984 chart accounts for particle size to diameter ratio (d_{50}/D) when calculating changes in the Durand deposition parameter, particularly for ratios between 0.003 and 0.04.

This correction is applied for pipe inclinations between -20° and 80°. Beyond this range, the pipe is considered vertical.

See Inclined Pipe Correction

A fundamental component of any solvable model, represented as a boundary node that provides fluid and temperature data for the solver.

Inlet boundaries are not manually assigned but automatically determined based on the node’s configuration to drive flow toward the system.

Some of these configurations are:

• When two Known pressure nodes at the same elevation are connected to each other, and one node has a higher pressure setting, the solver automatically selects the node with the higher pressure as the inlet boundary component.
• For boundary nodes both specified with the same pressure setting, the relative elevation between them also serves as a basis for selection.
• When using a known flow node, setting the flow direction to “Into Network” instructs the solver to treat that node as an inlet boundary. This forces the solver to calculate a boundary pressure that establishes the node as the fluid source.
• If a boundary node is connected to the suction side of a booster or flow control valve, it will also require the solver to use its data as inlet boundary.

User interface feature in FluidFlow for entering and editing data, displaying and configuring property tables, images, text, and other flowsheet objects.

Also known as transition flow, this regime is typically found to occur at Reynolds numbers between 2300 and 4000.

This flow regime is associated with unstable flow patterns, making it undesirable for fluid transport, heat transfer and measurement.

3D visualization option in FluidFlow achievable by engaging the Isometric cross hair button on the flowsheet settings toolbar.

The Joule–Thomson effect describes the temperature change (increase or decrease) of a gas as it expands.

The change in temperature ($\Delta T$) with a decrease in pressure ($\Delta P$) at constant enthalpy (H) is known as the Joule–Thomson coefficient (μ$_{JT}$).

FluidFlow uses the Peng Robinson equation of state to calculate this coefficient, which is expressed as:

μ_{JT} = (\Delta T/ \Delta P)_H

The value of μ_{JT} is typically expressed in °C/bar and depends on the gas’s physical properties, temperature, and pressure before expansion.

Nodes used to model pipe connections that combine, split flow, or change pipe direction which can either be:

• Connector
• Bends
• Tee or Wye
• Cross Junction

Except for connectors, all other junction can be automatically generated on the flowsheet when making pipe connections, subject to connection rule limitations.

For bends, tees and wyes, the calculation of pressure drop applies the K-factor pressure loss relationship:

\Delta P = K × (ρV²/2)

Where the pressure loss coefficient K can be evaluated using any of these junction pressure loss correlations:

• Idelchik
• Miller
• SAE
• Crane

Node for representing pressure loss coefficient. It represents the directly proportional relationship of head loss (or pressure drop) to the square of velocity arriving to the expression:

\Delta P = K × (ρV²/2)

Pressure loss coefficients can be applied across different fluids. According to DS Miller, these coefficients are not unique to a specific fluid but instead function as universal relationships to Reynolds number for a given geometry.

Where:

K values for different piping system equipment can be stored in the database for future application.

Node that represents a resistance coefficient derived from Crane TP-410, expressed by the following formula:

K_f = f_T (L/D)

Where:

L/D values for K_f nodes can be stored in the database for future application.

Boundary node in FluidFlow used to represent a flow condition at the system entrance or exit point.

The flow direction for this node is specified by user. When set to “Into Network”, the node becomes an inlet boundary with additional fields for fluid and temperature appearing.

The solver will calculate the pressure required to meet the defined flow.

Boundary node in FluidFlow used to represent pressure at the system entrance or exit point.

The flow direction for this node is automatically determined by the solver based on the model’s configuration. The solver analyzes the system to determine whether this node should drive flow into the network or receive flow from it.

Based on the defined pressure, the solver calculates the achievable flow rate at this node.

Boundary node in FluidFlow used to represent an outlet boundary with specific exit characteristics defined by a K factor.

General resistance node used to simulate pressure drop variability with flow for fittings, manual valves, piping equipment, or combinations thereof through the following relationship:

\Delta P = (\rho_{Ref}/\rho)^{n-1}(m/m_{Ref})^n\Delta P_{Ref}

Where:

Kv data can be stored in the database for future application.

Observed at Reynolds number less than 3000, this flow regime is characterized by smooth, orderly fluid motion where fluid moves in parallel layers with minimal mixing between layers.

Tab located in the data palette that provides descriptive status information about the most recent calculation. It displays any issues or adjustments made by the solver during calculation, including convergence errors, engineering hints, and calculation or component warnings.

A modified Reynolds number applied by FluidFlow for calculating friction factors of Herschel-Bulkley fluids. It is expressed by the equation:

R_{MR}= 4n'\rho VD / [\mu_w(3n'+1)]

Where:

Lowest acceptable flow rate for specific pump model needed to prevent recirculation, overheating, and other mechanical issues.

Typically specified in pump curve database entry as checkpoint during performance evaluation.

During calculations, the software displays a warning message if the pump operates below its specified minimum flow rate.

Dimensionless parameter applied by the Darcy – Weisbach equation that quantifies the friction loss incurred for a certain fluid, flow velocity, pipe size and length.

Calculation of friction factor is dependent on flow regime:

Laminar Flow:

f_D = 64/Re

Turbulent Flow (Colebrook (a) / Haaland (b) Equation):

1/√(f)=-2 Log [ε/3.7D+2.51/(Re√f)]     

1/√(f)=- Log [(ε/3.7D)^{1.11}+2.51/Re]     

Haaland equation is used when the user selects the non-iterative solution for friction factor calculation in the Calculation options.

Where:

For systems where flow regime falls within transition, a linear interpolation using the friction factor at the Reynolds number where laminar flow terminate and turbulent regime start is applied.

FluidFlow feature that automatically performs multiple calculations by using a range of values for an input parameter across one or more components.

Licensing option that allows a use of a license stored online accessed through the Login Named User Dialog by keying-in credentials.

Fluid whose viscosity is always constant at a given temperature.

In viscometry, it generates a linear shear rate vs. shear stress plot starting at the origin.

Correlations used to calculate head losses occurring between the flowing fluid and flow exposed conduit surfaces.

By Default, FluidFlow uses the the Darcy – Weisbach equation. However, these alternatives can also be applied in pipe components through the input editor:

• Shell – MIT
• Hazen – Williams
• Fixed Friction Factor (Darcy)

Components in FluidFlow hydraulic models where pipes connect, defining system topology and flow paths.

Standard pipe size designation used in FluidFlow for classifying pipes with different specifications.

Fluid whose viscosity changes with shear rate and hence not constant. Depending on the fluid itself and resulting stress from an applied shear, its viscosity may increase or decrease.

Modelled in FluidFlow using the following rheological models:

• Power Law
  \tau = K \gamma^n
• Bingham Plastic
  \tau = \tau_{BP} + \eta_P \gamma
• Herschel – Bulkley
  \tau = \tau_{HB} + K \gamma^n
• Casson
  \tau^{0.5} = \tau_{C}^{0.5} + \eta_C \gamma^{0.5}

Where:

Specialized friction loss correlations that takes into account the dependency of fluid viscosity with shear using non-Newtonian shear rate vs. shear stress relationships and empirical methods.

Correlations used to calculate head losses occurring between the flowing fluid and flow exposed conduit surfaces.

By Default, FluidFlow uses the the Darcy – Weisbach equation. However, these alternatives can also be applied in pipe components through the input editor:

• Shell – MIT
• Hazen – Williams
• Fixed Friction Factor (Darcy)

Slurry where solid particles remain uniformly suspended and do not settle during transport. Sometimes referred to as non-Newtonian slurries and typically modeled as a homogeneous mixture in FluidFlow.

Characterized with slurries having solid particles smaller than 75 microns.

Pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid.

Frequently used to control the rate of flow, speed, direction, shape, or the pressure of the stream that emerges from them.

Acronym for Net Positive Suction Head, a parameter used to design or examine pumps to predict the possibility of cavitation.

It refers to the difference between the pressure or head at the pump suction inlet and the fluid’s vapor pressure.

Acronym for Net Positive Suction Head Available, It refers to the difference between the pressure or head at the pump suction inlet and the fluid’s vapor pressure at a particular pump flow rate.

Refers to the booster shaft rotational speed which influence pump performance in accordance to affinity laws.

Circular plate device with a sized bore at the center inserted in pipes to create pressure drop to restrict or measure fluid flowrate.

2D visualization option in FluidFlow achievable by engaging the Orthogonal cross hair button on the flowsheet settings toolbar.

Pressure head at a point in the system, equivalent to sum of the elevation and static pressure.

An enclosed conduit used to transport fluids. These are circular in cross-section and available in widely varying sizes, wall thicknesses, and materials.

Pipes are specified in terms of their diameter and wall thickness, which can also be indicated by the schedule number.

Angle or gradient at which a pipe is installed relative to a horizontal plane.

In FluidFlow, this is expressed in degrees (°).

Pump type that creates work to increase fluid pressure by trapping a fixed volume of liquid in a chamber or cavity and then physically displacing it by mechanical means such as a piston, diaphragm, or gear in a repetitive cyclic process.

As the chamber decrease in size, the trapped liquid is forced out, generating flow and increasing its pressure to move toward the discharge.

Non-Newtonian fluid that demonstrates a non-linear shear rate vs. shear stress plot that starts from the origin.

Depending on the flow behavior exponent, its viscosity may increase (thickening at n> 1) or decrease (thinning at n<1) as shear is introduced.

Pressure differential between two points measured using the same reference point.

In Known pressure boundaries, this refers to the manner on pressure is defined: either as stagnation or static pressure.

Safety device that limits pressure in a system during abnormal conditions by releasing fluids to a safe location.

In FluidFlow, relief valves are sized according to orifice bore size. When automatic sizing feature is turned off, it can also be used to evaluate the performance of pressure relief valve for a particular model using manufacturer data.

Mass fraction of vapor in a fluid stream.

When inlet boundary fluid type is set to two phase, an input field for quality will appear while the field for defining temperature would be hidden.

The solver will calculate the corresponding temperature required to achieve the specified vapor quality at the inlet boundary pressure.

Ratio of bend radius to pipe diameter for pipe bends and elbows used as data for calculating pressure loss.

FluidFlow feature for importing component of data from excel sheets to streamline model setup.

This feature requires data to be formatted in accordance with FluidFlow’s input specifications.

Solver calculation setting found in the Gas tab of the Calculation options dialog box.

This feature addresses how pressure and temperature affect gas volumetric flowrate by allowing users to set standardized flow measurement conditions across components where flow is an input parameter. Users can select from:

• Standard Conditions (101325 Pa and 15°C)
• Normal Conditions (101325 Pa and 0°C)

Represents the ratio of the inertial force to the viscous forced exerted on the fluid.

This dimensionless parameter is applied to characterize flow regime by quantifying the momentum of a fluid or the inertial forces compared to the internal friction or fluid viscosity.

At high Reynolds number, inertial forces dominate leading to turbulent flow, while at lower values signify that viscous forces are influential, resulting in smooth, laminar flow.

It is calculated using the expression:

Re = DV\rho/\mu

Where:

Unwanted buildup of solid deposits on flow exposed surfaces of pipes, pumps, heat exchangers and other process equipment.

Pipe components in FluidFlow has the feature to model the impact of reduced flow cross section due to scaling. Users have the option of defining scaling by applying readily available information from the database or using an arbitrary value.

Sequence of user-defined instructions using a programming language to automate tasks, manipulate data or perform custom calculations.

FluidFlow’s scripting module enables this functionality using Pascal or Basic programming languages. This module allows users to create custom calculations using existing input and results data or manipulate flowsheet components.

Slurry containing particles that tend to settle under gravity and demonstrates complex flow behavior.

These slurry types apply specialized correlations to model impact of solids deposition and its non-monotonic friction loss behavior against flow.

Typically observed in slurries having solid particles greater than 75 microns.

See Deposition Velocity

Correlations for modelling the physical interaction of solids-liquid-pipe wall within a horizontal pipe which accounts for the following variables:

• Carrier fluid and Solids Density
• Carrier fluid viscosity
• Solids concentration
• Solids Bulk Density
• Solids Heywood Shape Factor
• Solids Sliding Bed Coefficient
• Solids Particle Size Distribution
• Solids Stratification
• Pipe Roughness
• Pipe Size

From the slurry tab of FluidFlow calculation options, any of these correlations can be used:

• Durand
• Wasp
• Wilson-Addie-Sellgren-Clift (WASC)
• Sellgren, Wilson Four Component Model
• Liu Dezhong
• $V_{SM}$
• $V_{50}$
• 4CM

Correlations for modelling the physical interaction of solids-liquid-pipe wall within a vertical pipe which accounts for the following phenomena:

• Local increase in solids concentration because of liquid and solid velocity slip
• Movement of solids towards or away the pipe wall

From the slurry tab of FluidFlow calculation options, any of these three correlations can be used:

• Vertical Pipe WASC Loss
• 4CM
• Spelay, Gillies, Hashemi and Sanders 2017 Collisional Stress Model

Alternative Newtonian friction loss correlation typically applied to high viscosity hydrocarbon and heated transport systems.

It uses an empirical relationship to determine a modified Reynolds number for calculating friction factors in laminar and turbulent flow regimes.

R_m = Re / 7742

Laminar flow friction factor:

f = 0.00207 / R_m

Turbulent flow friction factor:

f = 0.0018 + 0.00662 R_m^{-0.355}

Friction loss relationship:

P_m = C (f S Q^2)/D^5

Where:

General classification of components that cause sudden change of fluid velocity during transport. Typically caused by change in size of inlet and outlet pipes or by a sudden constriction.

These devices in FluidFlow belong to the classification:

• Thin Sharped-Edged Orifice
• Thick Orifice
• Inlet Nozzle
• Venturi Tube

Calculation framework in FluidFlow used for determining equipment specifications based on defined:

• Flow
• Pressure Rise
• Pressure Loss
• Economic Velocity
• Velocity
• Pressure Gradient

Also known as sprinkler heads, these are active fire protection devices that discharge water to a specific area to extinguish fires or provide cooling in case of fire emergency.

These devices can be modeled in FluidFlow as outlet boundaries to determine whether flow requirements for each destination can be met based on a defined exit pressure.

Pressure exerted by a fluid when brought to rest, combining static and velocity pressure.

In measurement terms, this is the pressure reading obtained from a pitot tube-type gauge where pressure is measured at the pipe’s center, a point where friction loss is zero and velocity is at a maximum.

One of the pressure models available in FluidFlow. This model is recommended for pressure-type boundary conditions, especially for systems with large storage tanks or atmospheric boundaries where the associated volume remains relatively constant over time and fluid velocity can be assumed negligible.

Pressure exerted by a fluid at rest.

In measurement terms, this is the pressure reading obtained from a gauge whose measurement is taken at the pipe wall, a point where fluid velocity is zero.

One of the pressure models available in FluidFlow. This model is recommended for systems that do not start at a physical boundary such as a vessel or reservoir but rather a particular location in a pipe network.

Graphical representation showing how total pressure drop in a system or component varies with flow.

These curves are generated in individual pipes or pumps accessible through the chart tab of the data palette or in parallel and series pump composite charts.

Fitting used to join three conduits that split or merge two flow streams.

Modelled in FluidFlow using any of these pressure loss relationships:

• Idelchik
• Miller
• SAE
• Crane

Predefined FluidFlow component configurations that can be saved and stored individually for use in future modelling activities.

See Intermediate Flow

Flow regime characterized by chaotic, irregular fluid motion where eddies and swirls dominate. Typically observed at Reynolds number of 4000 or higher.

Mechanical device installed in a piping system to regulate, stop, re-route or isolate fluid flow.

In modeling, valve flow resistance characteristics are defined using their K, Kf, Kv, or Cv values. Valve positioning data versus Cv or Kv can also be applied to accurately model valve performance.

In FluidFlow, these are the different valves that be placed in hydraulic models:

• Butterfly
• Diaphragm
• Ball
• Gate
• Globe
• Angle
• Ball Float
• Plug
• Pinch
• Y-Globe
• Needle
• Slide
• Penstock
• Fire Hydrant
• Three Way

Pressure at which a liquid begins to vaporize at a specific temperature.

This fluid property is commonly investigated in liquid transport systems where cavitation or two-phase flow issues are likely to occur.

Piping equipment featuring a constricted section that creates a “venturi effect” or the simultaneous pressure drop reduction and increased fluid velocity as the fluid passes across.

FluidFlow allows users to size these devices using flow or pressure loss sizing models to determine the required throat diameter for a specific throat length.

Alternatively, users can evaluate flow or pressure loss across a venturi with predefined throat diameter and length specifications.

FluidFlow feature for exporting calculation results, component data, and system information to Microsoft Excel format.

Pressure loss ratio factor that predicts the point at which flow becomes choked, where further pressure drop doesn’t increase flow due to sonic velocity limitations at the vena contracta.

This information is obtained from valve manufacturers and can be unique to certain valve types and models

Minimum shear stress required to initiate flow in non-Newtonian liquids following Bingham Plastic, Herschel – Bulkley and Casson rheology models.