THE MOUNT OF WIND TUNNEL

Introduction

Wind tunnel is typically large tubes with moving air inside. These tunnels are used for the purpose of copying the actions of an object in flight. Usually, wind tunnels are used by researchers to learn how aircraft will fly (U.K, 2008).  This device consists of tubular passage with the object under investigation mounted in the middle. Wind is made to flow past the object by a powerful fan system or any other means. The object under investigation, often called a wind tunnel object, is instrumented with appropriate suitable sensors. These sensors are used for measuring the pressure distribution, aerodynamic forces, or other aerodynamic-related characteristics. Although some wind tunnels are big enough to the extent of holding full-size versions of vehicles, the moving of air around the object makes it to look its really flying (I.S.U, 2008).

Problem statement

With respect to the above considerations, the purpose of this paper is to study the general effects of air moving past solid objects as well as how the result form this research is applicable in engineering field.

Customers and customer wants

Majority of the wind tunnels are applied in aerodynamics. Therefore the main customers of this research include;

• Aeronautic engineers
• Automotive engineers and,
• Outdoor skydiving facility manufacturing engineers
• Ship and submarine manufacturing engineers

With respect to the above users, the rise/mount of the wind tunnel has wider applications as far as customer needs are concerned. In the field of aeronautics, the main desires of customers are to own or travel in aircrafts which are safer and convenient to use. Thus, wind tunnels are used for the purpose of learning more about airplanes and how things move past air. For instance, one of the main tasks of NASA is improving air transportation. This device then helps them to investigate the ideas for ways of making aircraft better and safer for customers. Engineers can therefore test new materials and shapes for aircraft parts. Equally, prior to flying new airplane, aeronautic engineers must subject it in a wind tunnel so as to make sure that will fly as it is supposed to fly (U.K, 2008). 

On the other hand, customers also desire to travel in automobiles which are much safer. Because of this, automotive engineers use this device in order to access the effects of moving air on various parts for instance vehicle fume exhaust, dust collection systems and so on. This makes customers to be contented in using any automobile.

Quantitative engineering specifications

Engineering specifications are quantitative i.e. are measurable criteria which a particular product is designed to satisfy (Peter et al, 2013). Therefore, in order for them to be unambiguous and measurable, certain specifications ought to contain metric, engineering units and target value.

• Therefore, in this case, the dimensions of the wind tunnel are directly connected to the cross section of the test chamber.
• A squire cross-section of about 0.5m and moving air with a velocity of 30m/s is used.
• Hydraulic diameter is to be computed as D=2is calculated
• The length of the test chamber should be 0.5-3 times the hydraulic diameter
• Moreover, the length of the taste chamber is to be taken as being 2 timed D
• Chamfer the shape edges of the wind tunnel to 45 degrees so as to avoid the reduction of the velocity of the air and increase in boundary layer thickness (S.U, 2008).

List of potential conceptual solutions

For the wind tunnel to work effectively, a powerful fan/s must move air through the tube. Before that, the object under investigation is fastened in the tube so as to ensure that it doesn’t move. This object can either be a small model of a full-size aircraft or spacecraft or vehicle or a common object like a tennis ball (N.R.C et al, 1988).  

Then moving air around the object illustrates what would happen in case the object was moving past the air. The manner in which air will be moving can be studied in different ways i.e. using smoke or dye. Moreover, threads can also be attached so that they can show hoe air will be moving. Some special instruments are used in measuring the force of the air on the object (Peter et al, 2013).

Moreover, for it to work effectively, pressure loss should be considered. Thus the following should be noted;

• First, pressure loss in the constant cross-section area is due to friction.
• Friction and expansion causes pressure loss in the diffusers.
• Pressure loss in the corners of the wind tunnel is due to expansion and friction
• Complement solidity or porosity causes pressure loss in screens.
• Skin friction causes pressure loss in the nozzle (Peter et al, 2013).

 

 Recommendations

The design procedures of the wind tunnel ought to be taken into the following steps;

1) Defining the test section dimensions as well as the desired flow of air velocity by the test type

2) Designing of the wind tunnel component by the test section criteria

3) Computing the pressure of the components of the wind tunnel (Peter et al, 2013).

4) Estimating pressure losses from the wind tunnel circuit as being the function of the air flow velocity in all the testing sections i.e. in the closed and open configurations

5) Matching the components of the wind tunnel to commercial fans together with energy considerations.

6) In order to compute the velocity of the wind, the following formula is used

            Velocity of wind+ 8.1 (tan q)^^1/2

In connection to that, before the experiment starts, several processes should be taken into considerations. First, it is essential to noted that frictional and pressure drug acts on the wind tunnel. Frictional drug is due to the friction which acts in between the moving gas and the object. Pressure drug is basically the development of eddy currents which are as a result of the air/fluid passing through the object (Peter et al, 2013). This drag will be measured in the tunnel because frictional drag doesn’t get induced at low speeds.

Conclusion

To sum up, wind tunnels are regarded as being the measurement equipments which are used for studying the flow of gases around a body. The forces which are then generated by the air-body interaction through the use of this device assist in measuring the local and global wind tunnel flow velocities and temperature and pressure around that body. Its application ensures that all the structures for instance buildings, vehicles, and aircrafts are much better and safer to use.

 

 

Bibliography

Iowa State University, (2008). Computational and Wind Tunnel Studies of Shelterbelts for Reduction of Wind Flow and Wind-induced Loads on Low-rise Buildings. ProQuest Press

University of Kansas, (2008).Low Speed Virtual Wind Tunnel Simulation for Educational Studies in Introducing Computational Fluid Dynamics and Flow Visualization. ProQuest Press

Peter I, Roy D, & David S, (2013). Wind Tunnel Testing of High-Rise Buildings. Routledge Press

National Research Council (U.S.)., Smelt, R., National Research Council (U.S.)., & National Research Council (U.S.). (1988). Review of aeronautical wind tunnel facilities. Washington, D.C: National Academy Press.

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