Lab9 - Lift Coefficient for an AirfoilUsing an Integrated Pressure Distribution PDF

Preview

Summary

Lift Coefficient for an Airfoil
Using an Integrated Pressure Distribution
...

Description

Lift Coefficient for an Airfoil Using an Integrated Pressure Distribution By Quang Nguyen Partners: Huynh Anh, Aldo Fenalli, Kendall Shaw

School of Engineering

Laboratory 9 EGR 365 – Fluid Dynamics

July 7, 2017

Quang Nguyen EGR 365 Lab 9 Summary Report

1. Result and Discussion In this experiment, the lift coefficient at 4 °

angle of attack was determined and

the pressure distribution over a Clark Y-14 Airfoil was measured. The data that used to calculated experimental lift coefficient was shown in Table 1 and Table 2. Table 1: Data Table

c/C 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.075 0 0.075 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Pipe

Height (in)

Rake ΔHeight (in)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

4.6 5.3 5.8 6.4 7.2 7.6 8.2 8.7 8.9 1.3 3.7 3.4 3.2 3.2 3.2 3.2 3.2 3.2

-4.6 -5.3 -5.8 -6.4 -7.2 -7.6 -8.2 -8.7 -8.9 -1.3 -3.7 -3.4 -3.2 -3.2 -3.2 -3.2 -3.2 -3.2

Manometer Tube ΔHeight (in) 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2

Cp -0.4375 -0.65625 -0.8125 -1 -1.25 -1.375 -1.5625 -1.71875 -1.78125 0.59375 -0.15625 -0.0625 0 0 0 0 0 0

Table 2: Experimental Parameter Chord Length (in) Atmospheric Height (in) U-Tube Manometer Atmospheric (in) U-Tube Manometer Tank (in)

3.5 ±0.002 0 ± 0.05 0 ± 0.05 3.2 ± 0.05

Figure 1 shown the graph of experimental pressure coefficient versus the pressure openings location percentage of chord. From the graph, the trapezoid rule was employed

Quang Nguyen EGR 365 Lab 9 Summary Report 1

to calculate the

∫Cpd 0

c . The result of C

1

∫ C p d Cc

was found as 0.872. After

0

1

∫ C p d Cc

was found, lift coefficient,

C L , was calculated using the equation:

0

1

C L =cos ( α ) ∫ C p d 0

where

CL

c (1) C

was lift coefficient,

coefficient, and

c C

α

was angle of attack,

Cp

was pressure

was percentage of location of pressure openings over length of

chord. The experimental coefficient was found as 0.870.

Experimental Cp versus c/C -2 -1.5

Cp

-1 Cp

-0.5

0 0.5 -0.1

1

0.1

0.3

0.5

0.7

0.9

1.1

�/�

Figure 1: Experimental Cp versus Theoretically, using software, the graph of

c C

C p when angle of attack was 4 °

was shown in Figure 2. According to Figure 2, the value of lift coefficient was 0.916, which was closely matched with the experimental value. The percent difference between experimental and theoretical value of lift coefficient was 5.02%. The possible sources of

Quang Nguyen EGR 365 Lab 9 Summary Report

error in this experiment were human error in reading the value of pressure measurement, old equipment, and uncertainty in measurement equipment.

Figure 2: Theoretical graph and result using software 2. Conclusion The theoretical value of lift coefficient, which was 0.916, and experimental value of lift coefficient, which was 0.87 were closely matched with 5.02% difference. The possible sources of error in this experiment were human error in measurement, old equipment, and uncertainty in measurement equipment....