Modeling a heat exchanger using a porous isotropic blockage and a negative heat load

Heat exchanger 3d Model

Heat exchanger data:

Heat rejected from fluid to heat exchanger = 96KW
Cross sectional area in model = 1.946 m2
The Thickness (L) of the heat exchanger in the model is 0.214 m

The following was obtained from the manufacturer of the heat exchanger:

Heat exchanger data table

From the above information the following data points are obtained:

Data points extracted from the above heat exchanger table

The previous data is plotted to obtain DP/L vs V and fitted with a 2nd order polynomial

The previous data is plotted to obtain DP/L vs V and fitted with a 2nd order polynomial

An Isotropic blockage is prescribed to the heat exchanger air volume using the Head Loss and Permeability method.

the Head Loss and Permeability method equation

The values for h_loss and k can be obtained from the above equation and curve fit. Using data for air at 50C, the following was obtained.

Heat exchanger h loss and k values table

The previous values for head loss and permeability are entered in the flow blockage dialog box. A heat load is applied to the heat exchanger air volume using a value of -95kW.

Testing Results:

Case 1: mass flow = 3.44 kg/s

Case 1: mass flow = 3.44 kg/s

Case 2: mass flow = 4.345 kg/s

Case 2: mass flow = 4.345 kg/s