Fan (G)
Fan in the gas mains.
Description
Unit Fan (G) represents a fan in a gas network. You can model the torque and pressure gain on the fan as a function of static pressure and flow rate or by usage of tabular data (1D or 2D) for reference pressure, shaft speed and flow rate.
By default, flow and pressure gains are routed from port A to port B. Port C represents the fan housing and port R represents the fan shaft. You can specify the normal direction of shaft rotation in the Mechanical orientation parameters. If the shaft starts to rotate in the opposite direction, the pressure drop across the fan will drop to zero.
Parameterization by nominal pressure, flow rate and shaft speed
If the Fan parameterization is set to `Static pressure and flow rate at reference shaft speed', the block uses the analytical fan similarity laws and reference differential pressure to calculate the pressure rise from port A to port B:
where
-
- is the reference pressure drop. The block uses a quadratic approximation of the fan pressure drop values for the parameters Maximum static pressure gain at zero flow, Nominal static pressure gain and Maximum volumetric flow rate at zero pressure;
-
- shaft angular speed, - ;
-
- reference shaft angular velocity, Reference shaft speed parameters;
-
- geometric scale factor, parameters Fan diameter scale factor.
The shaft torque is calculated in the unit based on the reference mechanical power and fan similarity laws:
where is the ratio of pressure gain to fan efficiency:
If the Shaft power specification parameters are set to Fan efficiency
, the block uses a quadratic efficiency approximation between the peak fan efficiency and 0. The value of is the value of the Nominal efficiency parameter, which the block interprets as the peak efficiency. If the Shaft power specification parameters are set to Brake power
, the nominal efficiency of the fan is determined from the nominal effective power under peak or nominal conditions:
It is assumed that the efficiency is zero when there is no flow rate or when the flow rate reaches the maximum volumetric flow rate when there is no pressure rise. The unit uses the current flow rate to calculate the reference flow rate:
Parameterization of one-dimensional tabular data: pressure as a function of flow rate at reference shaft speed
If the Fan parameterization parameter is set to `1D tabulated data - static pressure vs. flow rate at reference shaft speed', the fan operation is modelled as a function of volumetric flow rate. The block interpolates the pressure gain from port A to port B from the 1D parameters Static pressure gain vector:
where
-
- gas density;
-
- reference density, the value of the Reference density parameters.
The shaft torque is calculated from the reference mechanical power and the fan similarity laws:
In the instantaneous flow rate block, is used to calculate the reference flow rate:
If during the simulation the instantaneous values of parameters (variables) are outside the tabulated data, the block extrapolates the pressure based on the average slope of the fan curves and the reference torque to the nearest point.
Parameterization of two-dimensional tabular data: pressure as a function of shaft speed and flow rate
If the Fan parameterization parameter is set to 2D tabulated data - static pressure vs. shaft speed and flow rate
, the pressure gain generated by the fan is modelled as a 2D function of volumetric flow and angular velocity. The block interpolates the pressure gain from port A to port B based on the two-dimensional parameter Static pressure gain table, dp(w,q):
The block calculates the shaft torque based on the reference mechanical power and fan similarity laws:
where the reference mechanical power is a function of the reference flow rate and the instantaneous shaft speed.
The instantaneous flow rate is used to calculate the reference flow rate:
If during the simulation the parameters (variables) values are outside the tabulated data, the unit extrapolates the pressure gain based on the average slope of the fan and reference torque curves to the nearest point.
*Missing data
If there are unknown elements in the table, use NaN
instead of these values. The unit fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Artificial numerical values should not be used as they distort the behaviour of the fan when operating in a given range. If there are unknown elements in your tabular data:
-
NaN
elements in the table must be contiguous. -
The positions of the
NaN
elements in the parameters Static pressure gain table, dp(w,q), Efficiency table, eta(w,q) and Mechanical power table, W(w,q) must be adjacent to each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Parameterization of two-dimensional tabular data: flow rate as a function of shaft speed and pressure
If the Fan parameterization parameter is set to 2D tabulated data - flow rate vs. shaft speed and static pressure
, the flow rate generated by the fan is modelled as a two-dimensional function of pressure and angular velocity. The block interpolates the flow rate based on the two-dimensional parameter Volumetric flow rate table, q(w,dp). The reference flow rate is defined as a function of the reference pressure increment and the current shaft angular velocity :
where the reference pressure rise is derived from the pressure drop across the fan:
The shaft torque is determined from the reference mechanical power and the fan similarity laws:
where the reference mechanical power is a function of the reference flow rate and the current shaft speed.
If during the simulation the parameters (variables) values go beyond the tabulated values the unit extrapolates the pressure based on the average slope of the fan and reference torque curves to the nearest point.
*Missing data
If there are unknown elements in the table, use NaN
instead of these values. The unit fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Artificial numerical values should not be used as they distort the behaviour of the fan when operating in a given range. If there are unknown elements in your tabular data:
-
NaN
elements in the table must be contiguous. -
The positions of the
NaN
elements in the parameters Volumetric flow rate table, q(w,dp), Efficiency table, eta(w,dp) and Mechanical power table, W(w,q) must be contiguous with each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and the lowest shaft speed.
Power and efficiency
You can specify the method of calculating the shaft power based on fan efficiency or effective power.
In the block, efficiency is defined as:
where is the effective power , or the mechanical power measured at the shaft:
In a block, the fluid power is defined as:
Torque is defined as follows:
Assumptions and limitations
-
If the shaft rotates in the opposite direction from the direction specified in the Mechanical orientation parameters, the pressure gain through the block will drop to zero and the results may not be accurate.
-
The block assumes that the fan is operating quasi-stationary.
-
The block models fan operation in the approximation of increasing static pressure, not total fan pressure.
Ports
Conserving
#
A
—
gas inlet port
gas
Details
Gas non-directional port associated with the fan inlet section.
Program usage name |
|
#
B
—
gas outlet port
gas
Details
Gas non-directional port associated with the fan outlet section.
Program usage name |
|
#
R
—
fan shaft
`rotational mechanics
Details
A mechanical non-directional port associated with a fan shaft.
Program usage name |
|
#
C
—
fan housing
`rotational mechanics
Details
A mechanical non-directional port associated with the fan housing.
Program usage name |
|
Parameters
Main
#
Fan parameterization —
model for calculating fan performance
Static pressure and flow rate at reference shaft speed
| 1D tabulated data - static pressure vs. flow rate at reference shaft speed
| 2D tabulated data - static pressure vs. shaft speed and flow rate
| 2D tabulated data - flow rate vs. shaft speed and static pressure
Details
Parameterization of fan characteristics:
-
`Static pressure and flow rate at reference shaft speed' - fan characteristics are calculated based on specified values of typical, nominal or allowable pressure rise and volume flow rate.
-
`1D tabulated data - static pressure vs flow rate at reference shaft speed' - fan characteristics are calculated from interpolation of pressure rise data as a function of volume flow rate.
-
2D tabulated data - static pressure vs shaft speed and flow rate
- fan characteristics are calculated from interpolation of pressure rise data as a function of shaft speed and volume flow rate. -
`2D tabulated data - flow rate vs shaft speed and static pressure' - fan characteristics are calculated from interpolation of volumetric flow rate data as a function of shaft speed and pressure rise.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Shaft power specification —
power method
Fan efficiency
| Brake power
Details
A method of determining the power of a fan:
-
Fan efficiency
- mechanical power is calculated from fan efficiency. -
Brake power
- mechanical power is set directly.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Nominal volumetric flow rate —
flow rate at reference shaft speed
m^3/s
| m^3/h
| cm^3/s
| mm^3/s
| ft^3/s
| lpm
| l/s
| gpm
| gal/s
| gal/h
Details
Volumetric flow rate through the fan at reference shaft speed under nominal, typical or design operating conditions.
Dependencies
To use this parameter, set the Fan parameterization parameters to `Static pressure and flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Nominal static pressure gain —
pressure increase at the reference shaft speed
Pa
| GPa
| MPa
| atm
| bar
| kPa
| ksi
| psi
| uPa
| kbar
Details
Pressure increase from port A to port B at reference shaft speed under nominal, typical or design operating conditions.
Dependencies
To use this parameter, set the Fan parameterization parameters to `Static pressure and flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
# Nominal efficiency — efficiency at reference shaft speed
Details
Nominal efficiency of conversion of shaft power to hydraulic power at reference shaft speed under rated, typical or design operating conditions.
Dependencies
To use this parameter, set the Fan parameterization parameter to `Static pressure and flow rate at reference shaft speed' and the Shaft power specification parameter to `Fan efficiency'.
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Nominal mechanical power —
power at nominal efficiency
W
| GW
| MW
| kW
| mW
| uW
| HP_DIN
Details
The mechanical power that drives the gas flow at a reference shaft speed under nominal, typical or design operating conditions.
Dependencies
To use this parameter, set the Fan parameterization parameter to `Static pressure and flow rate at reference shaft speed' and the Shaft power specification parameter to `Brake power'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Maximum static pressure gain at zero flow —
maximum pressure at the reference shaft speed
Pa
| GPa
| MPa
| atm
| bar
| kPa
| ksi
| psi
| uPa
| kbar
Details
Pressure rise from port A to port B at reference shaft speed when there is no flow through the fan.
Dependencies
To use this parameter, set the Fan parameterization parameters to `Static pressure and flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Maximum volumetric flow rate at zero pressure —
maximum flow rate at the reference shaft speed
m^3/s
| m^3/h
| cm^3/s
| mm^3/s
| ft^3/s
| lpm
| l/s
| gpm
| gal/s
| gal/h
Details
Volumetric flow rate at reference shaft speed and constant pressure.
Dependencies
To use this parameter, set the Fan parameterization parameters to `Static pressure and flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Reference shaft speed —
reference speed corresponding to the fan curve
rpm
| deg/s
| rad/s
Details
Reference shaft angular speed corresponding to the fan characteristic curve data.
Dependencies
To use this parameter, set the Fan parameterization parameters to `Static pressure and flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Volumetric flow rate vector —
vector of flow values corresponding to the fan curve
m^3/s
| m^3/h
| cm^3/s
| mm^3/s
| ft^3/s
| lpm
| l/s
| gpm
| gal/s
| gal/h
Details
Vector of volumetric flow values for one-dimensional interpolation of the fan characteristic curve. If the Shaft power specification parameters are set to `Brake power', the fan data may be outside the normal operating range and these values may be negative.
Dependencies
To use this parameter, set the Fan parameterization parameters to `1D tabulated data - static pressure vs. flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Static pressure gain vector —
vector of pressure rise for a given volume flow rate
Pa
| GPa
| MPa
| atm
| bar
| kPa
| ksi
| psi
| uPa
| kbar
Details
A vector of pressure rise values. Each element of this vector must correspond to an element of the Volumetric flow rate vector. The pressure gain is the increase in pressure from port A to port B at the reference shaft speed. If the Shaft power specification parameters are set to `Brake power', the fan data may be outside the normal operating range and these values may be negative.
Dependencies
To use this parameter, set the Fan parameterization parameters to `1D tabulated data - static pressure vs. flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
# Efficiency vector — efficiency vector for a given volume flow rate
Details
A vector of fan efficiency values. Each element of this vector must correspond to an element of the Volumetric flow rate vector. Efficiency is the ratio of hydraulic power to mechanical shaft power at a reference shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameter to `1D tabulated data - static pressure vs. flow rate at reference shaft speed' and the Shaft power specification parameter to `Fan efficiency'.
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Mechanical power vector —
mechanical power vector for a given flow rate, used to calculate the torque on the shaft
W
| GW
| MW
| kW
| mW
| uW
| HP_DIN
Details
Vector of shaft mechanical power values. Each element of this vector must correspond to an element of the Volumetric flow rate vector. The mechanical power is the power that drives the fan at the reference shaft speed. These values can be negative if the fan data is outside the normal operating range.
Dependencies
To use this parameter, set the Fan parameterization parameter to `1D tabulated data - static pressure vs. flow rate at reference shaft speed' and the Shaft power specification parameter to `Brake power'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Reference shaft speed —
reference speed corresponding to the fan curve
rpm
| deg/s
| rad/s
Details
Reference shaft angular velocity corresponding to the fan characteristic curve data (for 1D tabulated data - static pressure vs. flow rate at reference shaft speed).
Dependencies
To use this parameter, set the Fan parameterization parameters to `1D tabulated data - static pressure vs. flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Reference density —
gas density at which the reference fan operation was measured (for 1D tabulated data - static pressure vs. flow rate at reference shaft speed)
g/cm^3
| kg/m^3
| lbm/gal
Details
Gas density corresponding to the fan characteristic curve data.
Dependencies
To use this parameter, set the Fan parameterization parameters to `1D tabulated data - static pressure vs. flow rate at reference shaft speed'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
# Minimum shaft speed threshold as fraction of reference — threshold for minimum shaft speed
Details
Threshold for minimum shaft speed as a fraction of the reference shaft speed. The block uses this value to ensure that the shaft speed does not become 0
and cause a division by zero error in the expression for .
Dependencies
To use this parameter, set the Fan parameterization parameters to Static pressure and flow rate at reference shaft speed
or 1D tabulated data - static pressure vs. flow rate at reference shaft speed
.
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Shaft speed vector, w —
shaft speed vector (for 2D tabulated data - static pressure vs. shaft_speed and flow rate)
rpm
| deg/s
| rad/s
Details
Vector of shaft angular velocity values for 2D interpolation of fan characteristic curves.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - static pressure vs. shaft speed and flow rate'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Volumetric flow rate vector, q —
volume flow vector (for 2D tabulated data - static pressure vs. shaft_speed and flow rate)
m^3/s
| m^3/h
| cm^3/s
| mm^3/s
| ft^3/s
| lpm
| l/s
| gpm
| gal/s
| gal/h
Details
Vector of volumetric flow rates for 2D interpolation of fan characteristic curves. If the Shaft power specification parameters are set to `Brake power', the fan data may be outside the normal operating range and these values may be negative.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - static pressure vs. shaft speed and flow rate'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Static pressure gain table, dp(w,q) —
pressure increase for pressure parameterization
Pa
| GPa
| MPa
| atm
| bar
| kPa
| ksi
| psi
| uPa
| kbar
Details
Matrix at of pressure increment values for two-dimensional pressure increment interpolation. The pressure gain is the increase in pressure from port A to port B. If the Shaft power specification parameters are set to `Brake power', the fan data may be outside the normal operating range and these values may be negative.
The values and are the sizes of the corresponding vectors:
-
- number of elements in the Shaft speed vector parameters, w. The elements corresponding to zero flow rate must be arranged in strictly increasing order.
-
- number of elements in the Volumetric flow rate vector, q.
If there are unknown elements in the table, use NaN
instead of these values. The block fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Do not use artificial numerical values as they distort the fan behaviour when operating in this range. When usage of unknown elements:
-
NaN
elements in the table must be contiguous. -
The positions of
NaN
elements in the parameters Static pressure gain table, dp(w,q), Efficiency table, eta(w,q) and Mechanical power table, W(w,q) must be adjacent to each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - static pressure vs. shaft speed and flow rate'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
# Efficiency table, eta(w,q) — efficiency for torque parameterization
Details
Matrix at efficiency values for 2D torque interpolation. Efficiency is the ratio of the hydraulic power to the mechanical power of the shaft at the reference shaft speed.
The values and are the dimensions of the corresponding vectors:
-
- number of elements in the Shaft speed vector parameters, w.
-
- number of elements in the Volumetric flow rate vector parameters, q.
If there are unknown elements in the table, use NaN
instead of these values. The block fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Do not use artificial numerical values as they distort the fan behaviour when operating in this range. When usage of unknown elements:
-
NaN
elements in the table must be contiguous. -
The positions of
NaN
elements in the parameters Static pressure gain table, dp(w,q), Efficiency table, eta(w,q) and Mechanical power table, W(w,q) must be adjacent to each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameters to 2D tabulated data - static pressure vs. shaft speed and flow rate
and the Shaft power specification to Fan efficiency
.
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Mechanical power table, W(w,q) —
mechanical power for torque parameterization
W
| GW
| MW
| kW
| mW
| uW
| HP_DIN
Details
Matrix at mechanical power values for 2D torque interpolation. These values can be negative if the fan data is outside the normal operating range. The mechanical power is the power that drives the fan.
The values and are the dimensions of the corresponding vectors:
-
- number of elements in the Shaft speed vector parameters, w. The elements corresponding to zero flow rate should be arranged in strictly ascending order.
-
- number of elements in the Volumetric flow rate vector, q.
If there are unknown elements in the table, use NaN
instead of these values. The block fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Do not use artificial numerical values as they distort the fan behaviour when operating in this range. When usage of unknown elements:
-
NaN
elements in the table must be contiguous. -
The positions of
NaN
elements in the parameters Static pressure gain table, dp(w,q), Efficiency table, eta(w,q) and Mechanical power table, W(w,q) must be contiguous with each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameters to 2D tabulated data - static pressure vs. shaft speed and flow rate
and the Shaft power specification to Brake power
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Reference density —
gas density at which measurements were made (for 2D tabulated data - static pressure vs. shaft_speed and flow rate)
g/cm^3
| kg/m^3
| lbm/gal
Details
Gas density corresponding to the fan characteristic curve data.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - static pressure vs. shaft speed and flow rate'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Shaft speed vector, w —
shaft speed vector (for 2D tabulated data - flow rate vs. shaft_speed and static pressure)
rpm
| deg/s
| rad/s
Details
Vector of shaft angular velocity values for 2D interpolation of fan characteristic curves.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - flow rate vs. shaft speed and static pressure'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Static pressure gain vector, dp —
vector of pressure increase values (for 2D tabulated data - flow rate vs. shaft_speed and static pressure)
Pa
| GPa
| MPa
| atm
| bar
| kPa
| ksi
| psi
| uPa
| kbar
Details
Vector of pressure gains for 2D interpolation of fan characteristic curves. If the Shaft power specification parameters are set to `Brake power', the fan data may be outside the normal operating range and these values may be negative.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - flow rate vs. shaft speed and static pressure'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Volumetric flow rate table, q(w,dp) —
volumetric flow rate corresponding to the vectors of rotation velocity and pressure increase
m^3/s
| m^3/h
| cm^3/s
| mm^3/s
| ft^3/s
| lpm
| l/s
| gpm
| gal/s
| gal/h
Details
Matrix at volumetric flow rate values for two-dimensional volumetric flow rate interpolation. If the Shaft power specification parameters are set to `Brake power', the fan data may be outside the normal operating range and these values may be negative.
The values and are the dimensions of the corresponding vectors:
-
- number of elements in the Shaft speed vector parameters, w. The elements corresponding to zero flow rate should be arranged in strictly increasing order.
-
- number of elements in the Static pressure gain vector parameters, Dp.
If there are unknown elements in the table, use NaN
instead of these values. The block fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Do not use artificial numerical values as they distort the fan behaviour when operating in this range. When usage of unknown elements:
-
NaN
elements in the table must be contiguous. -
The positions of the
NaN
elements in the parameters Volumetric flow rate table, q(w,dp), Efficiency table, eta(w,dp) and Mechanical power table, W(w,dp) must be contiguous with each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - flow rate vs. shaft speed and static pressure'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
# Efficiency table, eta(w,dp) — efficiency for torque parameterization
Details
Matrix at efficiency values for two-dimensional torque interpolation. Efficiency is the ratio of the hydraulic power to the mechanical power of the shaft at the reference shaft speed.
The values and are the dimensions of the corresponding vectors:
-
- number of elements in the Shaft speed vector parameters, w.
-
- number of elements in the Static pressure gain vector parameters, Dp.
If there are unknown elements in the table, use NaN
instead of these values. The block fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Do not use artificial numerical values as they distort the fan behaviour when operating in this range. When usage of unknown elements:
-
NaN
elements in the table must be contiguous. -
The positions of the
NaN
elements in the parameters Volumetric flow rate table, q(w,dp), Efficiency table, eta(w,dp) and Mechanical power table, W(w,dp) must be contiguous with each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - flow rate vs. shaft speed and static pressure' and the Shaft power specification to `Fan efficiency'.
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Mechanical power table, W(w,dp) —
mechanical power for torque parameterization
W
| GW
| MW
| kW
| mW
| uW
| HP_DIN
Details
Matrix at mechanical power values for two-dimensional torque interpolation. These values can be negative if the fan data is outside the normal operating range. Mechanical power is the power that drives the fan.
The values and are the dimensions of the corresponding vectors:
-
- number of elements in the Shaft speed vector parameters, w. The elements corresponding to zero flow rate should be arranged in strictly ascending order.
-
- number of elements in the Static pressure gain vector parameters, Dp.
If there are unknown elements in the table, use NaN
instead of these values. The block fills in the NaN
elements by extrapolation based on the average slope of the fan curves. Do not use artificial numerical values as they distort the fan behaviour when operating in this range. When usage of unknown elements:
-
NaN
elements in the table must be contiguous. -
The positions of the
NaN
elements in the parameters Volumetric flow rate table, q(w,dp), Efficiency table, eta(w,dp) and Mechanical power table, W(w,dp) must be contiguous with each other. -
The `NaN' elements should be located in the upper right-hand side of the table, corresponding to the highest volumetric flow rate and lowest shaft speed.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - flow rate vs. shaft speed and static pressure' and the Shaft power specification to `Brake power'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Reference density —
gas density at which measurements were made (for 2D tabulated data - flow rate vs. shaft_speed and static pressure)
g/cm^3
| kg/m^3
| lbm/gal
Details
Gas density corresponding to the fan characteristic curve data.
Dependencies
To use this parameter, set the Fan parameterization parameters to `2D tabulated data - flow rate vs. shaft speed and static pressure'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
# Fan diameter scale factor — geometric scale factor
Details
Geometric scaling factor for increasing or decreasing the size of the modelled fan compared to a given fan parameterization. The scaling may be inaccurate for scaling factors having a value strongly greater or strongly less than 1
.
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Mechanical orientation —
direction of rotation
Positive angular velocity of port R relative to port C corresponds to normal fan operation
| Negative angular velocity of port R relative to port C corresponds to normal fan operation
Details
Normal fan operation with positive (or negative) direction of rotation of the shaft. By default, normal operation corresponds to the positive direction of rotation.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Inlet flow area (port A) —
port area A
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Cross-sectional area of the duct at the fan inlet.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Outlet flow area (port B) —
port area B
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Cross-sectional area of the duct at the fan outlet.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |