Effect of the Angle of Attack and Sideslip on the Blended Wing Body Aerodynamics at Low Speeds

The blended wing body (BWB) is becoming more attractive for modern-day researchers due to its capability to be more fuel efficient, less noisy, and have the better aerodynamic performance. However, a thorough flow investigation of such bodies under varying angles of attack and sideslip conditions is necessary to further enhance the above-mentioned advantages. To investigate the effect of the angle of attack and the sideslip angles, experiments and computations are conducted for a typical BWB at the free-stream velocity of 18 m/s corresponding to the Reynolds number of 58500 based on mean aerodynamic chord. The experimental work consisted of flow visualizations using oil flow techniques and measurements of the forces using an internal 5-component strain gauge balance. Computations were also made to solve numerical simulations using the commercial software Ansys Fluent. The results show a slight variation below 5% in the pressure distribution with change in the sideslip angle. Negligible variations in the lift-to-drag ratio were observed at the lower sideslip angles, whereas slight variations below 10% were observed in the higher sideslip cases. A reasonable agreement between computational and experimental oil flows was also observed, deducing a successful application of the present technique for the investigation of the angle of attack and the sideslip angle in a BWB body.