Experimental Investigation of lift to drag ratio between volumetrically equivalent fuselages

Abstract

To improve the overall lift to drag a new concept on fuselage of an Unmanned Aerial Vehicle (UAV) is investigated where the fuselage also provides some lift. To investigate the improvement of lift to drag two fuselages are considered, one is conventional cylindrical cross-section and the other is aerofoil cross-section. A number of fuselages models with a scale of I :32 with aerofoil cross-section and with conventional cylindrical cross section are manufactured in such a way that both models have the same volume. Same set of wings is used in both types of models so that the results can be used to show the comparison between the fuselages. To reduce the induced drag winglets are used in aerofoiled fuselage. All the three fuselages i.e., circular cross-sectioned, aerofoil cross-sectioned and aerofoil cross-sectioned with winglets are used for wind tunnel test. Lifts and drags are measured with the help of spring balance system for different angle of attack of the fuselages to find out the best fuselage corresponding to overall lift to drag ratio. From this result it is also found out what should be the best angle of attack of the fuselage at different speed during take off, flying and landing condition. Finally lifts and drags are also measured by pressure tapping around the fuselages at different angles of attack to verify the results found in spring balance system.