SHREYAS KOTIAN

• The first part governs the ignition of fuel droplets at elevated pressures for petroleum-based and biofuels. Experiments are further divided into normal gravity and zero gravity cases. Characteristics such as soot, soot shell, flame, droplet, and incandescence are examined using high-speed cameras also. • The second part of the study concerns with the ignition method of fuels. One is using spark electrodes and the other is by placing heated coils in close proximity. • Current study will investigate the range of variables for ignition including energy and duration to the ignition system and geometrical proximities of the energy source to the droplets and oxidizer concentration in the high-pressure chamber where actual ignition occurs.

• Goal of the present study is to investigate how the dimples on golf balls help in reducing drag as compared to a ball with no depressions on it. PIV technique was used for the same. • It is a well-known fact that the use of dimples on golf balls helps in reducing drag and maximizing range. Dimples cause the boundary layers to break which causes the fluid streamlines to lose their energy. In order to compensate for that it borrows energy from the surrounding air thus making the flow turbulent and allowing the streamline to complete its path. • The result of this is that the region of eddies and wakes gets smaller in size as the point of flow separation moves further downstream. • In the following study both a golf ball and a ping pong ball were studied in a flow of approximately 1 m/s corresponding to Re = 30,000. Using PIV 1500 image pairs were captured to get an estimate of the flow field which was then used to find the drag coefficient using the control volume technique. • It was found that the Cd value for the ping pong ball turned out to be 0.877 which is higher than the Cd value for the golf ball which was 0.795.

• Telescopic span morphing has been observed to augment the endurance of UAV’s by increasing lift to drag ratio while maintaining performance in other mission segments such as take-off, climb, and landing. • Interest of the study was to perform wing morphing on the Northrop Grumman RQ-4A Global Hawk and analyze how span extension affects variables like range, endurance, and drag. • Estimate up to what extent wing span extension is feasible subsequently giving maximum endurance. • In recent years, UAV’s and drones have been proposed to monitor weather conditions. With climate change being in the forefront it is essential that the weather is monitored so that calamities are prevented. Thus, based on the results obtained from the analysis of the Global Hawk, propose a design for a HALE UAV for coastal surveying.