The most important aerodynamical qualities that should be aimed at in wind tunnel design, are as follows: 1) constant and parallel direction of flow; 2) uniform velocity across all sections; 3) absence of turbulent motion; 4) constant velocity of flow. The above-mentioned qualities are all realized in a high degree in the Gottingen type of wind tunnel, with a parallel portion before the working section, the cross section of which is steadily reduced. It is shown in what follows, that the system can be applied to other wind tunnels, such as the N.P.L. or Eiffel type.

Wind tunnels are facilities in which the wind is produced by fans or by compressed air to study and measure the action of the air flow around a solid. There are two basic types of wind tunnels: the closed-circuit and the open-circuit. Open-circuits draw air from the ambient environment and exhaust it back to the ambient after exiting the fan, while in closed-circuit, the air repeatedly circulates through the tunnel. The closed-circuit design delivers improved efficiency and generates less noise, but it is more expensive and more difficult to manufacture. Wind tunnels are typically used in aerodynamic research to analyse the behaviour of flows under varying conditions, both within channels and over solid surfaces. The present book focus on uses and developments of wind tunnels. It consists on nine chapters presenting different studies on the design, uses and developments of the wind tunnel in different applications like wind turbines, building and aircraft models. The presented case studies and development approaches aim to provide the readers, such as engineers and PhD students, with basic and applied studies broadly related to the wind tunnels and its applications.

Three avenues for increasing the enthalpy attainable from scalable high performance arc heaters were studied: radiation loss reduction, magnetic control of arc terminations and geometry changes. The radiation loss work showed centerline arc column enthalpies over 30,000 Btu/lb. Because the arc column is optically thin, substantial reduction of radiation loss seems infeasible. Large arc devices will be limited more by radiation than small. Modest improvements in performance were achieved with magnetic interactions, which were found to be extremely complex. Proper proportioning of radial and axial field components was quite important, especially in maintaining scalability. Marked undesirable effects occurred when the auxiliary field coil was located near the electrode gap. Distinct performance improvements were achieved by changes in geometry, with air injection and chamber design the most significant for the low flow, high current region studied. (Author).

The book "Wind Tunnels and Experimental Fluid Dynamics Research" is comprised of 33 chapters divided in five sections. The first 12 chapters discuss wind tunnel facilities and experiments in incompressible flow, while the next seven chapters deal with building dynamics, flow control and fluid mechanics. Third section of the book is dedicated to chapters discussing aerodynamic field measurements and real full scale analysis (chapters 20-22). Chapters in the last two sections deal with turbulent structure analysis (chapters 23-25) and wind tunnels in compressible flow (chapters 26-33). Contributions from a large number of international experts make this publication a highly valuable resource in wind tunnels and fluid dynamics field of research.

The importance assumed in recent times by experimental supersonic wind tunnels, as well as the power required, has brought about the need for a study which would permit a comparison of the types tested and the principal theoretical plans.