recordGeneric_R_m_flow

Generic data record for thermal resistance that is used to compute the case temperature as a function of mass flow rate

Extends from Modelica.Icons.Record (Icon for records).

Information

Generic record for the case-to-inlet thermal resistance of a cold plate. Note that this resistance is relative to the inlet fluid temperature, which is the convention used in the Open Compute Project report by Chen et al. (2023). Thus, it is defined as

R = (Tcase - Tinlet) ⁄ Q̇

where Tcase is the case temperature, Tinlet is the coolant inlet temperature and Q̇ is the heat emitted by the cold plate. The case temperature is the external surface temperature of the component's packaging, typically the top-center point where a thermal interface material or heat sink is attached.

It turns out that the product R V̇ as a function of the volume flow rate V̇ is close to linear. Therefore, the model that computes the case temperature Buildings.Fluid.DataCenterEquipment.Racks.LiquidCooledSinglePhase.BaseClasses.CaseTemperature makes a data fit using R V̇ versus V̇. The parameter n determines the order of this polynomial, which is by default set to n=1.

References

Cheng Chen, Dennis Trieu, Tejas Shah, Allen Guo, Jaylen Cheng, Christopher Chapman, Sukhvinder Kang, Eran Dagan, Assaf Dinstag,Jane Yao. OCP OAI SYSTEM LIQUID COOLING GUIDELINES. 2023.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.VolumeFlowRate[:]V_flowVolume flow rate at user-selected points
Modelica.Units.SI.ThermalResistance[size(V_flow, 1)]RCase-to-inlet thermal resistance
Integern1Order of desired polynomial that fits the data points (V_flow, R*V_flow)

Revisions

  • December 16, 2025, by Michael Wetter:
    First implementation.