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Introduction to Thermal DesktopThermal Desktop is a program that allows the user to quickly build, analyze, and postprocess sophisticated thermal models taking advantage of lumped parameter, finite difference and finite element modeling methods. Thermal Desktop offers the thermal engineer full access to CAD-based geometry and CAD model building methods without expecting the thermal engineer to be a CAD expert and without compromising the unique aspects of thermal design analysis. Thermal Desktop allows the user build a thermal model in a CAD envrionment. Using CAD geometry and user definable material databases, Thermal Desktop automatically generates necessary capacitance and conductance inputs which are automatically formatted and seemlessly sent to SINDA/FLUINT, C&R Technoloiges' thermal/fluid solution engine. Model results are pass directly back to Thermal Desktop for postprocessing, plotting and evaluation. To provide a complete softare solution, Thermal Desktop has two add-on modules. The RadCAD® module calculates radiation exchange factors and orbital heating rates. Our second module FloCAD® generates flow networks and calculates convective heat transfer factors. RadCAD and FloCAD are licensed separately separately from Thermal Desktop allowing the user to tailor the software capabilities to optimally meet analysis needs. RadCAD can be purchased and licensed without Thermal Desktop. Thermal Desktop is available as a stand-alone, PC based, CAD program or as an AutoCAD® extension application. Powerful CAD techniques for generating geometry can be used for generating thermal models. Custom pull-down menus, toolbars, and dialog forms permit the construction and analysis of thermal models directly within the AutoCAD environment. Thermal Desktop require some knowledge of general CAD techniques. Model Building
Thermal Desktop contains a set of custom surface types that combine the features of CAD with the familiarity and convenience of TSS/TRASYS/NEVADA type surfaces. True conic surfaces can be created with multiple nodal breakdowns. These special surfaces contain grip points that can be selected to directly modify the surface geometry. The grip points in conjunction with snap features enable a new level of CAD-integrated model building. Thermal Desktop can analyze thermal models consisting of 3D faces, regular MxN meshes, and arbitrary polyface meshes. These surfaces may be created directly, or by using various mesh generation commands such as surfaces of revolution, ruled surfaces, and edge defined patches. Thermal Desktop is not limited to just conic surfaces like many other thermal programs. Thermal Desktop can also import, display, and analyze existing TRASYS, TSS, NEVADA, IDEAS FEM, FEMAP and NASTRAN models. Native CAD Model Building Methods If the engineer is familiar with CAD-based drawing methods such as revolving curves, Boolean operations, ruling, etc., they may used to generate geometry directly in Thermal Desktop. These geometric surfaces may be used directly in the radiation model, or these surfaces (in addition to arbitrary construction lines, arcs, and points) may be used as scaffolding to which RadCAD surfaces can be snapped. Using Thermal Desktop Surfaces Like TRASYS, Thermal Desktop offers a list of geometric surfaces such as cones, cylinders, disks, rectangles, spheres, and paraboloids that can be used to generate geometric models using basic dimensions such as length, radius, etc. While these surfaces can be input using specific dimensions, the user may also stretch, shrink, rotate, etc. these surfaces directly on the screen via the mouse-selected "grip points
Using Existing or Imported CAD Drawings 2D or 3D CAD drawings, whether imported or native, can be used to help develop a Thermal Desktop model. There are several ways to exploit such a drawing. First, all or part of the drawing can be used directly as part of the thermal model by selecting surfaces and assigning them Thermal Desktop data such as node and property information. Or, the drawing can be used indirectly as scaffolding to which Thermal Desktop surfaces can be snapped. For example, the user can select key dimensional points on the drawing, drag an appropriate Thermal Desktop surface over to it, and using grip points snap the Thermal Desktop surface onto the highlighted "gravity" points on the drawing. The underlying CAD drawing (or at least those parts not used in the RadCAD model) can then be left as they are, discarded, or perhaps hidden on another (temporarily) invisible layer. Thus, an appropriate radiation model can be rapidly built without the thermal engineer having to even know the exact underlying dimensions. If the design changes, the drawing can be reimported and the Thermal Desktop model can be stretched or shrunk as needed to fit the new dimensions. Importing FEM modelsThermal Desktop allows the user to take an existing structural model from NASTRAN, IDEAS, or FEMAP and to use it to construct a thermal model. Feature Highlights Thermophysical Property Databases and Aliases The property databases files store the thermophysical and optical properties. A number of options are available for properties including: temperature dependence; pressure dependence for conductivity; angular dependence for optical properties; phase change; effective emissivity for MLI; and ablation for non-charring ablation and sublimation. The user may opt to change the property databases from one case to another to examine the effects of property degradation (end-of-life), perhaps.
Property aliases allow the user to specify a name linked to a property. The alias name is used in place of a property and points the property in the database. The property used in a solution can be changed by changing the property associated with the alias. As an example, the alias name ‘Insulation’ may be used in a model for all instances of the insulation; the material referenced by the alias can be easily changed from polystyrene to glass fiber if material trades are being performed or if the design dictates the change in material. Case Manager The Case Set Manager organizes conduction generation, radiation analysis, fluid flow network generation, SINDA execution, and post processing under a single one-click operation. Multiple cases may be defined and executed sequentially, automating and simplifying large analysis jobs. The case set manager also allows access to SINDA/FLUINT's Advance Design modules for design optimization, test correlation and reliability engineering.
Model Browser The model browser allows access to all features of the model in a tree format. From the model browser, the user may view network hierarchies from multiple points of view, edit and delete network objects, plot results, and review results and results summaries. The model browser is an extremely powerful tool allowing access to objects that may not be visible in the graphics area. Parametric Modeling Thermal Desktop is designed as a parametric design tool. Input fields for surface parameters, assembly positing, optical and material properties, network elements, and orbital data will accept numerical values or expressions using arbitrary user-defined variables. Parametric trade studies and optimizations are easily executed, especially when managed using case sets. A revolutionary new dynamic link between SINDA/FLUINT and Thermal Desktop allows SINDA/FLUINT to command Thermal Desktop to recompute radks, heating rates, conduction, and capacitance data on the fly from within a SINDA/FLUINT execution. Using the SINDA/FLUINT Solver, optimizations may now be performed that include optical properties and geometric sizing as design variables. Thermal models may be automatically correlated to test data, varying all aspects of the model including capacitance, conduction and radiation values. Optimizations may be performed to ideally locate boxes or electronic components, to size radiators, or minimize weight - now including radiation dependent design variables. Feature Summary Please see the Thermal Destkop page for a more complete list of features.
Add-on Modules
Unique Capabilities of the Thermal Desktop Suite
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