Wind tunnel is a test facility used to simulate the flight conditions. It allows us to make a reusable prototype and test it in the tunnel in low cost. Hypersonic wind tunnels operate at hypersonic speeds ie, with a mach number greater than 6. For doing experiments, it is necessary to maintain a constant pressure in the settling chamber of the tunnel so that we get the desired mach number and m...

The philosophy of physical modeling of atmospheric flow is discussed with special emphasis on wind-tunnel simulation techniques. The governing equations of motion are analyzed for application of laboratory testing. Key similitude parameters such as Reynolds, Froude, Rossby, and Richardson numbers, as applied to wind-tunnel requirements, are discussed. Prevalent boundary condition requirements, ...

An experimental study was conducted to investigate the performance of wind turbines sited over hilly terrains in order to elucidate the underlying physics to explore/optimize design of wind turbines sitting over complex terrains for higher power yield and better durability. The experiments were conducted in an atmospheric boundary layer wind tunnel with wind turbines sited over a two-dimensiona...

A recirculation aerosol wind tunnel was designed to maintain a uniform airflow and stable aerosol size distribution for evaluating aerosol sampler performance and determining particle penetration through protective clothing materials. The oval-shaped wind tunnel was designed to be small enough to fit onto a lab bench, have optimized dimensions for uniformity in wind speed and particle size dist...

Feeder is one of the airships of the Multibody Advanced Airship for Transport (MAAT) system, under development within the EU FP7 project. MAAT is based on a modular concept composed of two different parts that have the possibility to join; respectively they are the so-called Cruiser and Feeder, designed on the lighter than air principle. Feeder, also named ATEN (Airship Transport Elevator Netwo...

Synchronous wind-induced pressures, measured in wind-tunnel tests on model buildings instrumented with hundreds of pressure taps, are an invaluable resource for designing safe buildings efficiently. They enable a much more detailed, accurate representation of the forces and moments that drive engineering design than conventional tables and graphs do. However, the very large volumes of data that...

An investigation is presented of Mach 12 flow over a wind tunnel model of a tether connecting an aerobraking spacecraft to an inflatable drag device. The study was undertaken to support numerical simulations employed in the design of a “ballute” (balloon-parachute) aerobraking device currently being developed by Ball Aerospace and NASA. The attachment point of the tether to the ballute is subje...

An automatic rotor trim control system was developed and successfully used during a wind tunnel test of a full-scale UH-60 rotor system with Individual Blade Control (IBC) actuators. The trim control system allowed rotor trim to be set more quickly, precisely and repeatably than in previous wind tunnel tests. This control system also allowed the rotor trim state to be maintained during transien...