Applications of Lightweight Models Based on Stereo-Lithography for Transonic Wind-Tunnel

Abstract

Strength and stiffness of current lightweight models based on stereo-lithography (SL) could not meet experimental requirements of the transonic wind tunnel test. Therefore, a composite structural wind tunnel model is proposed, which is constructed by the internal metal framework and outer photopolymer resin configuration. Taking a lightweight AGARD-B model as an example, its structural strength and stiffness verified results were investigated under transonic wind-tunnel test environments, and its aerodynamic characteristics were also analyzed by comparing with those of the metal models. It is proven that applications of the lightweight models strengthened by metal framework are feasible for the transonic wind tunnel. The results indicate that the aerodynamic characteristics of the lightweight models at small angle of attacks (−2° ≤ α ≤ 2°) are similar to the metal models and is not interfered by different stiffness, and they have slight disagreement at larger angle of attack (2° < α ≤ 8°). In addition, the method decreases the test models’ processing cycle by approximately 69%, weight by approximately 38.9%, and manufacture cost greatly. It increases inherent frequency of the test models by approximately 73.2% avoiding resonance of the test system. The lightweight models based on SL show convenience and promise in preliminary aerodynamic studies and initial selection aircrafts configuration with complex structure.

Keywords:

• lightweight models
• stereo-lithography
• transonic wind-tunnel
• aerodynamic characteristics
• composite models
• composite structure
• mechanics capability

Acknowledgments

The authors are pleased to thank Pro Li Di-chen for many helpful comments and for suggesting the theoretical analysis and model design. They also wish to thank Xi’an Jiao Tong University for giving help on model design and manufacturing, and Transonic Aerodynamic Institute of China, Aerodynamics Research and Development Center for affording experimental apparatuses. The researched work was supported by Government funds.