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

Abstract

PurposeIn 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/approachInternal 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.FindingsThe 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/implicationsStiffness 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/valueThis 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.

A Review of Similitude Methods for Structural Engineering

“…In order to improve the structural integrity of RP models and reduce the manufacturing period and cost, in Refs. [278] and [279], a preliminary design and manufacturing technique is introduced. This technique is applied to hybrid high-speed wind-tunnel models with an internal frame and an outer resin, fabricated, respectively, with a conventional method and stereolithography.…”

Low Observable Uncrewed Aerial Vehicle Wind Tunnel Model Design, Manufacturing, and Aerodynamic Characterization

“…In contrast, the FDM model with chromium coating had accurate results comparable to the conventional steel model. Yang et al [14] reinforced the photopolymer resin material with an internal metallic structure to reduce the weight and avoid the resonance phenomenon. They reported that the RP models suffered from deformation at a higher speed, particularly the thin regions such as the wing tip, which resulted in variations in the wind tunnel results.…”

Convergence of transonic wind tunnel test results of the AGARD-B standard model

“…Standard models are also used to provide baselines for correlation of results from different wind tunnels [1][2][3], to check data repeatability over time [4], for checkouts of wind tunnel systems after repairs or modifications, for the assessment of wall interference effects [5,6], for verification of new measurement techniques or devices [7], for the validation of new model manufacturing technologies [8][9][10], for training of wind tunnel personnel [11]. Besides, results from wind tunnel tests of standard models are used as test cases for the verification of computational-fluiddynamics (CFD) computer codes [12].…”