Trex Enterprises, San Diego (Trex.com), designed and delivered a prototype hazard-detection system for helicopters in only 14 weeks. The company evaluated four major cooling-system configurations in less than a month, evaluated various concepts for vibration isolation in less than five weeks, and successfully tested prototypes on a UH-1 helicopter. The company used the I-deas NX Series of 3D modeling software from UGS Inc., Plano, Tex. (ugs.com), to design concepts and quickly evaluate them against requirements. The software performs coupled fluid-thermal and dynamic-response evaluations of design concepts.
"The hazard-detection system is powered by sensitive electronics that must be protected from a wide range of external temperatures and high vibration," says George Houghton, senior engineer. "And to keep the project interesting, a tight schedule did not allow time for physical testing to validate design concepts."
Thermal and dynamic-analysis meshes were built on Parasolid models of the enclosure and electronic components, which were read into NX MasterFEM. NX Electronic System Cooling software was used for coupled fluid-thermal analyses. Cooling-system design was simplified by decoupling the internal and external fluid-thermal analyses. Heat-transfer coefficients from the external analysis were mapped directly to the internal model. Associativity with the solid models let the team make geometry changes and quickly see them in the thermalanalysis mesh.