[Fluent Inc. Logo] return to home search
next up previous contents index

32.3.40 Define/User-Defined/Heat Exchanger Group...

The Define/User-Defined/Heat Exchanger Group... menu item opens the Heat Exchanger Group panel.



Heat Exchanger Group Panel


The Heat Exchanger Group panel allows you to modify or define a heat exchanger core group.

figure

Controls

Name   specifies the name of a new heat exchanger group.

Fluid Zones   contains a list of all the fluid zones.

HX Groups   contains list of the heat exchanger groups. (This item will appear only for NTU model.)

Model Data   contains all the parameters to be specified for the model.

Primary Fluid Flow Direction   
Width, Height, Depth   specifies the width, height and the depth of the gas flow direction.

Connectivity   allows you to define the upstream and downstream connections.
Upstream   specifies the upstream heat exchanger group.

Downstream   specifies the upstream heat exchanger group.

Heat Transfer Model   allows you to select either the simple-effectiveness-model or the ntu-model.

Core Porosity Model   specifies whether default values are chosen for the core porosity model.

Edit...   opens the Core Porosity Model panel (see Section  7.25.3) for the definition of a new core porosity model.

Heat Exchanger Performance Data   contains the parameters for heat transfer.

Heat Transfer Data...   opens the Heat Transfer Data Table panel (see Section  2e).This panel allows you to define the heat transfer for different primary and auxiliary fluid flow rates. This item will appear for NTU model only.

Velocity Effectiveness Curve...   opens the Velocity Effectiveness Curve panel in which you can define the effectiveness of the heat exchanger core ( $\epsilon$ in Equation  7.25-11). This item will appear for simple effectiveness model only.

Auxiliary Fluid Temperature   specifies the coolant fluid temperature.This item will appear for NTU model only.

Primary Fluid Temperature   specifies the gas stream fluid temperature.This item will appear for NTU model only.

Geometry   contains parameters to define the macro grid.

Width, Height, Depth   specifies the width, height and the depth of the heat exchanger.

Number of Passes   specifies the number of passes.

Number of Rows/Pass   specifies the number of rows per pass.

Number of Columns/Pass   specifies the number of columns per pass.

View Passes   displays the macro grid. (This button becomes available after you click Set.) The path of the coolant is color-coded in the display: macro $0$ is red and macro $n-1$ is blue.

Draw Grid   toggles between displaying and not displaying the grid when the macro grid is displayed (using the View Passes button). The Grid Display panel opens when Draw Grid is selected.

Update from Plane Tool   updates the Coolant Inlet Direction and Pass-to-Pass Direction from the plane tool orientation. The Width, Height, and Depth will also be updated. See Section  27.6.1 for information about using the plane tool.

Auxiliary Fluid Inlet Direction   specifies the direction in which the coolant enters the heat exchanger. See Figure  7.25.6.

Pass-to-Pass Direction   specifies the direction in which the coolant moves at the end of each pass through the heat exchanger. See Figure  7.25.6.

Auxiliary Fluid   contains inputs to specify the properties of the coolant.

Properties Method   specifies the method to specify the coolant properties. You can choose from constant-specific-heat and user-defined-enthalpy.

Specific Heat   sets the specific heat of the coolant ( $c_p$ in Equation  7.25-16). This option is available when you choose constant-specific-heat.

Enthalpy UDF   sets the enthalpy as defined by the UDF selected from the drop-down list.

Auxiliary Fluid Flow Rate   sets the flow rate of the coolant ( $\dot{m}$ in Equation  7.25-16).

Initial Temperature   sets an initial guess for the inlet temperature ( $T_{_{\rm in}}$ in Equations  7.25-11 and 7.25-16). This value is specified only if Fixed Heat Rejection is selected.

Inlet Pressure   sets the coolant inlet pressure. This value is specified only if user-defined-enthalpy is selected.

Inlet Quality   specifies the value of $x$ in Equation  7.25-20.

Pressure Drop   specifies the value of $p_{in}$ in Equation  7.25-21. This value is specified only if user-defined-enthalpy is selected.

Supplementary Auxiliary Fluid Stream   specifies properties of the supplementary auxiliary stream.

Supplementary Mass Flow Rate   specifies the supplementary fluid flow rate as constant, polynomial or piecewise-linear.

Supplementary Flow Temperature   specifies the supplementary fluid temperature as constant, polynomial or piecewise-linear.

Supplementary Flow Quality   specifies the supplementary fluid quality.

Create   saves all the settings in the panel.

Delete   deletes the group that is selected in the HX Groups list.

Replace   changes the parameters of the already existing group that is selected in the HX Groups list.

Set...   opens the Heat Exchanger Model panel, in which you can define a new heat exchanger core model or read one from an external file.



Core Porosity Model Panel


The Core Porosity Model panel allows you to modify or define a heat exchanger core model. This panel opens when you click Edit... in the Heat Exchanger Group panel.

figure

Controls

Name   specifies the name of a new heat exchanger core model.

Database   contains a drop-down list of all heat exchanger core models that are currently available.

Gas-Side Pressure Drop   contains parameters that define the air-side pressure drop.

Minimum Flow to Face Area Ratio   sets the value of $\sigma$ in Equation  7.25-2.

Entrance Loss Coefficient   sets the value of $K_c$ in Equation  7.25-2.

Exit Loss Coefficient   sets the value of $K_e$ in Equation  7.25-2.

Gas Side Surface Area   sets the value of $A$ in Equation  7.25-2.

Min Cross Section Flow Area   sets the value of $A_c$ in Equation  7.25-2.

Core Friction Coefficient   sets the value of $a$ in Equation  7.25-3.

Core Friction Exponent   sets the value of $b$ in Equation  7.25-3.

Change/Create   saves the settings in the panel and adds the new model to the Database list.

Read...   opens the Select File dialog box, in which you can select an external file containing a predefined heat exchanger core model.


next up previous contents index Previous: 32.3.39 Define/User-Defined/Heat Exchanger...
Up: 32.3 Define Menu
Next: 32.3.41 Define/User-Defined/1D Coupling...
© Fluent Inc. 2006-09-20