Drag Power Measurement

GE322

429101961

GE322

GE322

GE322

EXPERIMENT NO . several: DRAG PRESSURE

EXPERIMENT NO . 3: MOVE FORCE

1 ) Objectives

* Computation of speed profile inside the wake of the two-dimensional tube. * Estimate the pourcentage of drag and match up against values inside the literature and from the pressure balance. installment payments on your Introduction

DragВ is an unavoidable consequence associated with an object shifting through a substance. Drag may be the force generated parallel and in opposition towards the direction of travel to get an object going through a fluid. Drag could be broken down into the following two components: 2. Form dragВ (or pressure drag) - influenced by the shape associated with an object going through a smooth * Skin area friction -- dependent on the viscous rubbing between a moving area and a fluid, created from theВ wall shear stress. [3]

[4]

The drag agent is a function of several parameters like shape of your body, В Reynolds NumberВ for the movement, В Froude number, В Mach numberВ andВ Roughness of the Surface. [5] Items drag coefficients are mostly outcomes of trials.

3. Apparatus and Methods

3. 1 Apparatus:

Figure 1: blowing wind tunnel

Physique 2: manometer inclined 45 degree in H2O mm

Physique 3: speed readout in m/s.

Determine 4: measure in hg cm

Physique 4: barometer in hg cm

Determine 5: thermometer in Level Celsius

Number 5: thermometer in Level Celsius

Number 6: standard circular tube 3cm high 2 . your five cm in diameter.

a few. 2 Methods and Approaches:

At the start, we measured the area temperature and pressure to calculate the density in the air inside the laboratory place using thermometer* and barometer** shown in figures 4& 5. Making use of the wind tube as demonstrated in Figure1 we measured pressure and controlled velocity. At first, we measure the primary conditions to work with them being a reference pertaining to future measurements. Then all of us set the wind tunnel at a many velocities*** and wrote over the readings in the manometer displayed in fig2. 4. 3 Uncertainties:

*Thermometer = В± 1 degree

**Barometer = В± five hg cm

***Speed readout = В± 2 . five m/s

4. Outcomes and Talks

Equation you can be used to estimate the drag force

FD=ПЃwu2dy-ПЃUв€ћAв€ћ (1)

ПЃ is air flow density (kg/m^3), w is width in the cylinder (m), u velocity of the movement near the cylinder (m/s), Uв€ћ velocity with the flow in free stream (m/s), Aв€ћ area of tube with rake (m^2).

Calculate the velocity (u) by using numeric integration by simply Simpson rule as shown in equation 2

(2). [1]

To calculate the speed (u) in the dynamic pressure we used equation several

u=2*Po-PПЃ (3)

Podynamic pressure (pa), L static pressure (pa).

By simply Substituting the Valuables with the drag pressure we worked out from equation 1 in Equation 5 we worked out the pull Coefficient to compare with number 10.

CD=FD0. 5ПЃUв€ћ2A (4)

CD move coefficient, A face area of the cylinder (m^2).

Shown in figures being unfaithful, 8& 7 are the effects of the velocities across the wind tunnel in several motor rates, which can be seen; on the speed readout displayed in number 3 by simply integrating the values numerically (equation 2) the pull force could be calculated.

Figure 7

Determine 8

Number 9

four. 1 Uncertainties:

SD=inx2i-x2mn-1 Formula 5 exactly where (SD) is a stander deviation, xi assessed value, xm mean benefit, n number of measure's. Up=tв€ќ/2, v*SDn

Formula 6: Up uncertainty.

Pressure total= В±12. 2 Water mm.

Pressure static= В± 2 . 5 H2o mm.

Air density= В± zero. 004 kg/m^3.

u= В± 6 m/s

FD= В± 0. 99 N

your five. Conclusions

your five. 1 Synopsis:

Setup quality and have all parameters, calculate velocity from energetic pressure equation, take deferent runs and calculate doubt, set it in a chart and compare with previous testing.

5. two Conclusion:

5. The faster the circulation goes the greater drag pressure becomes. * The opposite costs the pull coefficient; the faster the flow goes the lower the drag agent becomes. 6th.

APPENDIX...

References: [1] http://en.wikipedia.org/wiki/Simpson%27s_rule

[2] Fluid mechanics fox, McDonald

[3] http://www.symscape.com/lift-force-and-drag-force

[4] TheВ National Aeronautics and Space AdministrationВ (NASA) http://www.nasa.gov/

[5] Engineering resource website http://www.engineeringtoolbox.com/drag-coefficient-d_627.html