Development of a Practical Holistic Vehicle Thermal Model

Thermal modeling for military applications has historically focused on vehicle thermal signature or component engineering evaluation. The modeling tools vary drastically depending on the intended purpose. This paper identifies a modeling approach that produces a holistic vehicle thermal model applicable to signature evaluation, HVAC heat load assessment, and component thermal load evaluation. BKL-Prevu, Eclectic, and MuSES greatly simplify the modeling process and make it possible to model the complete vehicle system. BRL Prevu enables component selection and geometry manipulation. Eclectic uses a surface sampling process against existing CAD geometry to produce a well-conditioned mesh. MuSES obtains the models thermal solution using a finite difference approach. Models can now incorporate electronics and crew thermal footprints in conjunction with power train and environmental sources. This makes a total energy balance analysis possible. Conversion of chemical to mechanicalelectrical to thermal energy is predictable and traceable throughout the system. This paper discusses the model building process for a holistic vehicle thermal model applicable for signature and engineering analysis. Key issues such as model fidelity, mesh construction, and vehicle component omission are investigated. Integration of BKL-Prevu and Eclectic is demonstrated. The Bradley is used to illustrate the model building capability of this suite of computer codes.