The Drag Features of the Wind Tunnel - Essay Example

            The main purpose of the experiment is mainly to determine the drag features of different shapes beneath low-speed airflow. Moreover, it assesses the Reynolds numbers coupled with certification of the model prototype criterion.

Theory

            The prevailing tunnels are employed in the determination of the aerodynamic characteristics of the underlying bodies. Moreover, the tunnel entails the effuser, contraction section, and operating section coupled with the diffuser, and fan.

            The drag is the force of the body resulting from the fluid that resists motion within the direction of the travel of the existing body. Moreover, the drag ought to oppose force within the opposite direction in order to maintain or escalates the velocity of the object. The drag on the body resulted from pressure drag and corresponding friction drag. Pressure drag normally emanates from the disturbance of the new flow stream as it passes the prevailing body thus developing the turbulent wake. Pressure drag relies on the roughness of the surface, the shape of the prevailing body coupled with the Reynolds number of the flow, and the corresponding effect of the supplementary body. The pressure relies on the prevailing roughness of the surface, the shape of the objects, and the underlying Reynolds number of the existing flow coupled with the influence of the supplementary of the body.    Moreover, the friction drag is normally measured for the objects moving at the flow velocity within the vicious which results in extremely low Reynolds numbers.  

            In case the fluid stream flows of the body correspond to the surface of the prevailing body, the boundary layer segregates the surface resulting formed from the turbulent. The net force from the pressure drag is normally developed from the pressure of the relatively lower stagnation location of the body. Moreover, the pressure drag is diminished in case the separation takes place on the back due to the occurrences of the corresponding reduction. 

            The drag is designated as 22 when the drag force is 22 where d designates drag force ( N), and Cd depicts the drag coefficient. The density of the underlying medium is expressed as Si Unit of kg/ m3. The velocity of the object is designated as V and the projection area.

Procedure

            The first specimen was mounted on the open hemisphere within the wind tunnel struts offered on the three components balance. The zero mark was adjusted to the position of the counterbalance weights till the bubbles within the levels of the spirit were centralized with the underlying jockey. The wind tunnel was started and the dial was adjusted to a speed of 20%. The measurement reading of the manometer for the drag force was recorded. The procedure was repeated with the augmentations of the speed the10percentage. The calibration was steady and the scale was converted into the reading of the drag force by utilizing the wind tunnel calibration curve in the determination of the velocity of the underlying air flow from the corresponding reference static pressure reading.

Equipment

            The equipment utilized in the experiments was a wind tunnel, 200 inclined manometers, a Calibration system,  Rough and  Smooth round shaped objects, and  Flat or Straight Disks.

Discussion

            Drag force normally acts on the direction of the opposing motion thus being considered aerodynamic friction. The rough ball values for the existing drag coefficient attained utilizing identical via the slope of the graph. Moreover, the slope depicts the experimental error values. The prevailing drag coefficient against the Reynolds numbers uses the logarithmic scale. The alteration within the drag coefficient of the open hemisphere coupled with the circular disc results in the Reynolds numbers, which are identical to the values on the moody chart. Moreover, the total drag of the body results from the pressure drag and corresponding friction drag. Pressure drag occurs because of the underlying disturbance of the existing flow stream that results when the body develops a turbulent wake.

            Moreover, friction drag occurs due to the existence of thin layers of fluid on the surface body. Moreover, the magnitude of the prevailing of drag coefficient for the pressure drag majorly emanates from the shape of the body, Reynolds’s number, and the influence of the underlying bodies coupled with the surface roughness. The error in the measurement results from the balancing of the underlying weight of the wind tunnel.

Conclusion

            The experiment aids in learning and determination of the prevailing drag coefficient for the object of diverse shapes by utilizing the underlying wind tunnel.