Formation flight investigation for highly efficient future civil transport aircraft

Formation flight could greatly assist the air transport industry in tackling the challenges of environmental impact, excessive reliance on fuel and overcapacity. Previous studies have shown drag reductions leading to significant fuel savings for aircraft in formation relative to their solo flight. Safety is guaranteed with the use of extended formation distances, and practical implementation issues could be solved in the near future. Since studies so far have focused on existing aircraft configurations and technology, a case study using a strut-braced wing airliner was carried out to ascertain its applicability to less conventional craft. The present results did not indicate such clear-cut benefits. If formation flight is to be successful and beneficial for the next generations of aircraft, it will be vital to consider its interaction with new technologies developed for highly efficient operation, in particular those aimed at reduction of aircraft drag such as laminar flow, and to do so early in the design of aerospace vehicles and wider systems

Experimental and analytical investigation of radiation-induced natural convection in the near shore regions of lakes and reservoirs

Radiation-induced natural convection can play an important role in developing mixing and flow exchange within lakes and reservoirs that are well-protected from wind and have a long residence time. In the daytime, although incoming solar radiation transfers the radiative energy uniformly across the water surface, the bathymetry variation between the near shore and deep water regions creates a horizontal temperature gradient, leading to a horizontal convective motion. In addition, as the incoming light penetrates, its intensity attenuates with increasing depth according to Beer’s law. In near shore regions where the water depth is less than the light penetration depth, there exists residual radiation that is absorbed by the bed and re-emitted back to the water body as a heat flux. Therefore, a relatively warmer water layer is formed near the bottom and may become unstable leading to a vertical convective flow. Thus, net transport and mixing in such water bodies in daytime is promoted by these flows, the characterisation of which is the aim of this thesis. In Chapter 2, the vertical convective flow alone is studied on a laboratory scale using concurrent shadowgraph and Particle Image Velocimetry (PIV) measurements and experimental results are compared with previously developed scales. The 3D linear stability of this flow is investigated using a frozen time model in Chapter 3. The effect of different parameters on the critical conditions and the resulting flow pattern are evaluated. Further, the numerical and laboratory experimental determinations of critical wave numbers are compared. In Chapter 4, the coupled convective flow is examined on a laboratory scale using the same concurrent visualisation technique. The flow development, flow structure and its dependency on off-shore distance are quantified and compared with previously developed scales. Chapter 5 concludes the present study through reviewing the main results and providing suggestions for future work

Principles of Maximum Support for Groups Endangered of Victimization in the Iranian Legal System

Groups endangered of victimization are more vulnerable than other people of the society in terms of physical and social characteristics. These groups fall into five main categories, including children, women, the elderly, the disabled, and minorities. This article seeks to lay the foundations of maximum support for these groups in the Iranian legal system. It seems that there is still no consistent view in the Iranian legal system of protecting specific victims. This dispersion is due to the lack of justification of criminal policymakers for the need for maximum, comprehensive and discriminatory support for these groups. The foundations presented in this article are based on the concepts of human rights, the globalization of rights and the rights of Islam, on the basis of which it is possible to form a discriminatory criminal policy in support of groups vulnerable to victimization