Investigation of Rapid Manufacturing Technology Effect on Aerodynamics Properties

Original scientific paper Nowadays, rapid manufacturing methods are widely used in order to produce wind tunnel test models. Dimension accuracy, surface roughness and material strength are important parameters affecting aerodynamic properties of the models. In this research, applications and capabilities of two rapid manufacturing methods used in design and development of wind tunnel test models, built to measure aerodynamic coefficients have been investigated. In this experience, the AGARD-B model and the nose-body-tail vehicle configuration have been chosen. The first model was fabricated from metal and ABS-M30 material by machining and fused deposition modelling. The other model, AGARD-B, was fabricated by the three dimensional printing process. To improve strength and stiffness of the models and maintain balance, metal inserts have been used. Models are built to the least thickness in order to achieve acceptable dimensional accuracy and surface roughness. Aerodynamic coefficients of hybrid models including drag force, lift force and pitching moment under different angles of attack and specified speed have been measured and compared with standard models. Results imply that hybrid models developed by rapid manufacturing methods can be used for measurement of aerodynamic coefficients and calibration of wind tunnels; hence save production cost and time. Minor deviation of aerodynamic coefficients observed in hybrid models compared to metal models, can be pertained to the bending of the hybrid models under large angles of attack.