A preliminary design and manufacturing study of hybrid lightweight high-speed wind-tunnel models

Purpose - In view of the strength and stiffness deficiencies of current photopolymer resin models under high aerodynamic loads, the purpose of this paper is to introduce a preliminary design and manufacturing technique for hybrid lightweight high-speed wind-tunnel models with internal metal frame and surface photopolymer resin based on rapid prototyping (RP). Design/methodology/ approach - Internal metal frame structure was designed to be of regular configurations that can be conveniently fabricated by conventionally mechanical manufacturing methods. Outer resin components were designed to meet configuration fidelity and surface quality, which were fabricated by RP apparatus. Combination of aerodynamics and structure was utilized to accomplish structural design, strength and stiffness calibration and vibration analysis. Structural design optimization and manufacturing method of the validated hybrid AGARD-B models were studied by analysis of manufacturing precision, surface quality processing and mechanical capability. Findings - The method with internal metal frame and outer resin has dramatically improved the overall strength and stiffness of RP parts of the hybrid AGARD-B model, and it is suitable to construct the high-speed wind-tunnel models with complex internal structure. The method could decrease the model's weight and prevent resonance occurrence among the models, wind-tunnel and support system, and shorten processing period, and also it leads to decrease in manufacturing period and cost. Research limitations/implications - Stiffness of thin components for outer resin configuration is somewhat poor under high aerodynamic loads in a high-speed wind-tunnel test, and the effect of deformation of the components on the experimental results should be taken into account. Originality/value - This method can enhance the versatility of using RP technique in the fabrication of high-speed wind-tunnel models, especially for experimental models with complex structure. Aerodynamic and structural combination design and structural optimization for hybrid models make RP techniques more practical for manufacturing high-speed wind-tunnel models.