Question

Experiment (7) Drag Force TASK DETAILS Students must use the following equation in order to calculate the drag force on a cylindrical sample placed inside a wind tunnel at varying velocities 1 For CopAV Where: Cp is the drag coefficient p is the density of the fluid through which the body is moving (Pair = 1.225 kg/m?) v is the velocity of the body relative to the fluid A is the projected cross-sectional area of the body perpendicular to the flow direction (that is, perpendicular to v). TASK 1 TABLE 1: Drag force Measurement (8 marks) Diameter (m): Span (m): Projected Area (m²): Velocity (m/s) Drag Force, FD Drag Coefficient, CD 4 8 12 16 20 24

Answer 1

0 Given, Fo= 2 Co PAV? Co- Drag Coefficient P- density of fluid (Pair = 1.225 kg/mp) V- Velocity of body relative tofluid A- Projected cross-sectional Area • Cylindrical sample Diameter (m) Span (m) - 0.0um =D = 0.103m - L Projected Area (m²) LXD = 4.12 x103 m? A=4.12x10 ?m? Table 1: Drag force measurement Diamerorcm): 0.0ym Span (m): 0.103 m Projected Area (m): 4.12x10-3mm velocity (m/s) Drag force (FD) Drag coefficient (ce 0.25 0.01 4 8 0.62 12 0.2) 0.58 16 0.37 0.57 20 0.49 0.49 24 0.65 0.45

calculations: Fo= 3 ° Co PAV 2 2 Fo Coa PAVL V = 4 mis 280.01 X 1000 Co = = 0.25 1.225 x 4.1224 V=8mis 3 CD = 2x0.1 x1000 1.225x4112 x 84 = 0.62 (3) V=12mls > Co= 2x 0.21 X1000 = 0.58 1.225 X4.12X12" क v=16mls Co= 2X0.37 X1000 1.225 X4,12x16 = 0.57 V- 2omis - Co = 2x 0.49 X1000 = 0.49 1.225 x 4512X 201 (G V=2umls Co = 2x0.65 x1000 0.45 1.225x4.12.24

Date : Page No.: 101661 Scale Yaxis Tem O OSN 1024 A 0104 004 AR ye libety mia
Describe the graph: As from the equation given drag force equation FD is propotional to V²

From the the above graph we can see the curve is parabolic curve only.

So, Our observation is relevent to theriotical form.

3.As stated C_D values between 0.7-1.1 but from the experiment our max C_D is 0.62 error might happen because of not properlly calibrated instruments,surrounding temperature(cooler) might not be ambient as density value changes rather than1.225kg/m^3,Dimensional minute error in specimen.