Unmanned aerial vehicle is the most widely used aircraft technology due to its eminent applications in various fields like in military for surveillance, patrolling and rescue operations, agriculture and civil uses like food delivery, Aerial photography etc. There are two main categories of UAVs; Fixed-wing UAVs and multi-rotor UAVs. There are some issues which arise with conventional aerial vehicles like the absence of enough runway in rural areas and dense forests. Vertical take-off and landing (VTOL) UAVs have the advantages of both fixed-wing and fixed rotor type aircraft. These types of aircraft are more suitable for such applications where lack of runway and dense forests are major issues. This review article mainly focuses on the work done in the domain of design and analysis of vertical take-off and landing (VTOL)

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In this current era of technology VTOL UAVS is an emerging technology that is becoming popular for its variety of applications like Agriculture, Civil, and military for Surveillance, rescue missions, and patrolling. These types of aircraft came into existence as the solution to many issues like lack of runways in rural areas and dense forests. VTOL UAV is a hybrid of a helicopter and fixed-wing aircraft because it has the functionality of both types of aircraft. These aircraft possess high hovering efficiencies like a helicopter and a better cruising speed like a fixed-wing aircraft with an enhanced payload capacity. Many interesting applications of these aircraft is attracting researchers to work in this field. In this paper, a CFD approach has been adopted for the analysis of TURAC tilt-rotor type VTOL UAV with the help of XFLR software.

Nowadays the higher fuel efficiency is a major concern in every developing field of technology and it is also a cause for the development of lightweight materials. There are many applications in which it is required to join two dissimilar lightweight materials. Friction stir welding (FSW) is the most crucial development for such types of applications. This technique helps in overcoming the challenges raised during the joining of two dissimilar materials due to their incompatibility with conventional welding techniques. The lightweight materials developed with the help of friction stir welding (FSW) have applications in various industrial sectors like automotive, electronics, shipbuilding, railways, marine, and many others. It is inevitable in joining the different grades of materials like magnesium alloys, aluminum alloys, and low carbon steels without any weld defect. The thermal properties like heat generation and peak temperature also have a significant effect on the quality and strength of the weld joint. The thermal properties change the microstructure of the weld material and influence the mechanical properties of the welded material. This provides Temperature controlling methods so as to reduce the surface temperature and hence reduce the defects in the welded material. This present review article is based upon the summary of the work carried out by different researchers in the field of thermal modeling of the friction stir welding (FSW).