Experimental data are presented for the parasite drag of various helicopter fuselage components, such as skids, external fuel tanks, and tailplane. The experiments were conducted at the KNRTU-KAI T-1K wind tunnel, investigating four versions of a fuselage similar to the ANSAT helicopter. It was found that for the range of pitch angles −10°≤ ≤ 10°, the skids added 80% to the drag of the bare fuselage, while the tailplane increased the drag by 20%. At the same conditions, external fuel tanks were found to add 48% to the clean fuselage drag. A simple rotor hub with a tail support added 74% to the bare fuselage in the range of pitch angles −8°≤ ≤ 6°. Streamlining the rear fuselage was found to reduce the drag by 16% over the range of pitch angles −10°≤ ≤ 10°. Apart from the parasite drag, ideas for drag reduction are also discussed. Nomenclature

This paper proposes a new wind turbine concept suitable for low-speed winds. The design is studied using a combination of wind-tunnel experimentation and aerodynamic theory. After processing the experimental results, and after comparison with theory, the optimal conditions for the operation of the turbine are identified. Experimental and theoretical results suggest that the design offers a realistic alternative to conventional horizontal axis wind turbines. In addition, the proposed turbine has good power efficiency at low wind speeds, and is suitable for deployment in areas not yet favoured by wind farm developers.

In this paper, wind tunnel experiments are combined with Computational Fluid Dynamics (CFD) aiming to analyze the aerodynamics of realistic fuselage con¦gurations. A development model of the ANSAT aircraft and an early model of the AKTAI light helicopter were employed. Both models were tested at the subsonic wind tunnel of KNRTU-KAI for a range of Reynolds numbers and pitch and yaw angles. The force balance measurements were complemented by particle image velocimetry (PIV) investigations for the cases where the experimental force measurements showed substantial unsteadiness. The CFD results were found to be in fair agreement with the test data and revealed some §ow separation at the rear of the fuselages. Once con¦dence on the CFD method was established, further modi¦cations were introduced to the ANSAT-like fuselage model to demonstrate drag reduction via small shape changes.

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