modelAir
Information
This is a partial model of an IT rack with air-cooled components. The air cooling component with integrated fans is based on Buildings.Fluid.DataCenters.Racks.Air.Rack_P.
The model has fluid ports for the air cooling loop.
For air cooling, portAir_a and portAir_b serve as the inlet and outlet ports.
The input PAir specifies the power consumption for the air-cooled IT equipment.
Note that PAir does not include the power to operate the fan, as this is an output of the model.
The model provides two power consumption outputs.
The output PAirTot is the total electric power consumed by air-cooled IT, including fan energy.
The output PAirFan is the electric power consumed by the fan for air-cooled IT.
This is a partial model because it does not connect the outlet port air.port_b
of the air-cooled component to the model output portAir_b.
This connection must be made by the model that extends this partial model.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Performance data | |||
| Buildings.Fluid.DataCenters.Racks.Hybrid.Data.AirRearDoorHexPassive.Generic | dat | Performance data | |
| Dynamics › Air cooling | |||
| Modelica.Fluid.Types.Dynamics | energyDynamicsAir | Modelica.Fluid.Types.Dynamics.DynamicFreeInitial | Type of energy balance for air-cooled component: dynamic (3 initialization options) or steady state |
| Modelica.Units.SI.Time | tauAir | 2 | Time constant of air outlet temperature at nominal flow |
| Initialization › Air cooling | |||
| Modelica.Units.SI.Temperature | TAir_start | 293.15 | Start value of air temperature |
| Fan controller | |||
| Buildings.Fluid.DataCenters.Racks.FanControllers.Types.Strategy | fanControl | Buildings.Fluid.DataCenters.Racks.FanControllers.Types.Strategy.Load | Type of fan control strategy |
| Real[:,:] | fanSpeed | [0.0, 0.0; 1.0, 1.0] | Load and fan speed matrix (1st column normalized IT load, 2nd fan speed), e.g., fanSpeed=[0, 0; 0.5, 0.7; 1, 1]) |
| Modelica.Units.SI.Temperature | TAirOut_set | dat.air.TOut_nominal | Set point temperature for rack outlet air |
| Real | k | 1 | Gain of fan PI controller |
| Modelica.Units.SI.Time | Ti | 60 | Integrator time constant of fan PI controller |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | portAir_a | Air cooling inlet port | |
| Modelica.Fluid.Interfaces.FluidPort_b | portAir_b | Air cooling outlet port | |
| Modelica.Blocks.Interfaces.RealInput | PAir | Power consumed by air-cooled IT | |
| Modelica.Blocks.Interfaces.RealOutput | PAirTot | Electric power consumed by air-cooled IT, including fan energy | |
| Modelica.Blocks.Interfaces.RealOutput | PAirFan | Electric power consumed by fan for air-cooled IT |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.DataCenters.Racks.Air.Rack_P | air | Air-cooled rack component |
Contents
| Name | Description |
|---|---|
 MediumAir | Medium for air cooling loop |
Revisions
-
September 29, 2026, by Michael Wetter:
First implementation.