This paper investigates the preliminary wing design of Unmanned Aerial Vehicle (UAV) using a two step optimization approach. The first step is a single objective aerodynamic optimization whereas the second step is a coupled dual objective aerodynamic and structural optimization. In the single objective case, airfoil geometry is optimized to get maximum endurance parameter at a 2D level with max...

Insect wing shapes are diverse and a renowned source of inspiration for the new generation of autonomous flapping vehicles, yet the aerodynamic consequences of varying geometry is not well understood. One of the most defining and aerodynamically significant measures of wing shape is the aspect ratio, defined as the ratio of wing length (R) to mean wing chord (c). We investigated the impact of a...

in this work, the mechanism for fracture of brittle substances such as rocks under a uniform normal tension is considered. the oriented straight micro-cracks are mostly created in all the polycrystalline materials resulting from the stress concentrations. the present work focuses on the interactions of the pre-existing micro-cracks, which can grow and propagate within a rock-like specimen. the ...

Tip-mounted propellers can increase wing aerodynamic efficiency, and the concept is gaining appeal in context of hybrid electrical propulsion for greener aviation, as smaller lighter motors help with mitigating structural drawbacks a tip engine installation. A numerical study propeller effects on aerodynamics herein illustrated, considering different power configurations Regional Aircraft wing....

Due to their good mechanical properties composite materials are increasingly applied for the construction of lifting surfaces in maritime industry. However, besides improving strength weight ratio a structure, anisotropic material can also exhibit bend-twist coupling, when exposed higher loads. In order experimentally measure fluid structure interaction, object investigation needs same loadings...

In this work, the mechanism for fracture of brittle substances such as rocks under a uniform normal tension is considered. The oriented straight micro-cracks are mostly created in all the polycrystalline materials resulting from the stress concentrations. The present work focuses on the interactions of the pre-existing micro-cracks, which can grow and propagate within a rock-like specimen. The ...

An extensive experimental study is conducted to examine effects of different winglet-shapes and orientations on the vortex behind a wing, static surface pressure over the wing, and wing wake of a swept wing at various angles of attack. Four types of winglets, spiroid (forward and aft), blended, and winggrid are used in this investigation. Wing static surface pressure measurements are obtained f...

An analytical treatment to quantify the losses captured in the induced power factor, k, is provided for flapping wings in normal hover, including the effects of non-uniform downwash, tip losses and finite flapping amplitude. The method is based on a novel combination of actuator disc and lifting line blade theories that also takes into account the effect of advance ratio. The model has been eva...

The influence of the wing root junction on laminar separation bubble forming suction surface a semispan NACA 0018 cantilevered from wind tunnel test section wall is studied using flow visualisations, particle image velocimetry and pressure measurements at chord Reynolds number 125 000 an angle attack 6 $^\circ$ . boundary layer upstream turbulent, spanwise extends well beyond thickness. Substan...