WAYS TO BETTER PROJECT

 

Method 1-Prediction of Drag from Wake Measurements

1.Making the cylinder rough

A rough surface acts as turbulator. Turbulators induce turbulence in the layer of air next to the round area or its boundary layer. In some situations, a turbulent boundary layer reduces drag

2.Laminar flow has less drag drag but Turbulent flow has more drag

Laminar flow has less drag but Turbulent flow has more drag initially but also better adhesion, and therefore is less prone to separation. Therefore, if the shape of an object is such that separation occurs easily, it is better to turbulate the boundary layer (at the slight cost of increased drag) in order to increase adhesion and reduce eddies (which means a significant reduction in drag). A good example are dimples on golf balls.

 

lMethod 2-Measurement of the Normal Pressure distribution on the body

l1.Pressure loss between section two and one

In order to account for and minimize this effect Section I (an imaginary section), is chosen far behind the body such that the pressure is equal to the free-stream pressure. Therefore, the net pressure forces acting on this new control surface will be zero. The general conservation law can then be written without considering the effects contributed by pressure.

 

2.Acquire additional measurements taken for the drag forces, between section 2 and 1

The measurement due to normal pressures acting the body will be a good approximation to the total drag. But taking data from integrations at additional points will increase the accuracy of the experiment.

Vapor Jet Streams

(More costly, but visually effective for better understanding)

l1.Flow Visualization

Flow visualization techniques such as Schlieren, Pressure Sensitive Paint, Oil Flow, Tufts, Sublimation, Skin Fricion Interferometry, Laser Vapor Screen and Liquid Crystal can be obtained by appropriately positioning 2.35-foot diameter optical quality windows in the test section sidewalls. Still and color video capability are provided.

l2.Aerosol Generators

Aerosol Generators: Research often depends on the steady generation and injection of aerosols into the wind tunnel. Aerosol generators are used in the facility to produce most types of air contaminants present in natural and industrial environments Aerosols are generated by mechanical dispersion of powders, atomization of liquids, vaporization/condensation, and combustion processes. Commonly used aerosol include sonic nozzles for solids and powders; ultrasonic, two-fluid, and spray nozzles for liquids; nebulizers; fluidized bed generator, vibrating orifice generator, a computer-controlled combustion system; controlled vaporization/condensation processes.

l3.The Operating feed system

The Operating feed system (dry material feeders, liquid pumps) selected specifically for the requirements of individual projects. Mono-disperse aerosols, consisting of single-sized particles, are generated using vibrating orifice aerosol generators or by nebulizing microspheres. These aerosols provide the opportunity to test aerosols by particle size, the aerosol characteristic often most significant with respect to the transport and fate of aerosols.