The writer is very fast, professional and responded to the review request fast also. Thank you.
Presentation/PPT
27/08/2022
College of Aeronautics | worldwide.erau.edu
All rights are reserved. The material contained herein is the copyright property of Embry-Riddle
Aeronautical University, Daytona Beach, Florida, 32114. No part of this material may be
reproduced, stored in a retrieval system or transmitted in any form, electronic, mechanical,
photocopying, recording or otherwise without the prior written consent of the University.
AERO 309 – Module 4 Homework
1. In the book and presentations, we used dimensional analysis to derive the expression
L=q∞Scl. Now use dimensional analysis to derive M=q∞Sccm.
2. Use the following airfoils from the back of the book: NACA 1412, NACA 2412, NACA
4412, NACA 0006, and NACA 0009. For this question, use the airfoil data that is closest
to a Reynolds number of 6 million. Make sure you are using the correct curve. DO NOT
use the “Standard roughness” or flap curves.
a. For each airfoil, what is the maximum percent camber, the location of the
maximum camber, and the maximum percent thickness?
b. Using the airfoil data in the back of the book, what is the αL=0, cl at α=0, and cm at
α=0 for each airfoil?
c. From the information in (b), what can you say about the effect of camber? What is
special about the lift and moment for the symmetric airfoils?
d. For the symmetric airfoils, use the data in the back of the book to find clmax and
αstall.
e. From the information in (d), what is the effect of thickness on the lift curve?
3. Use the provided pressure coefficient distribution and Excel
a. Plot the Cp distribution. Make sure to use the convention where the Cp axis is
flipped (i.e. the negative Cp values are above the x-axis). Include your name in the
plot title.
b. Find the minimum (most negative) Cp value.
c. Use the trapezoidal rule to find cl. Since the chord length in the provided
distribution is 1, the integral to find cl is simplified. cl=∫01Cp,l dx-∫01Cp,u dx
d. Explain the steps you took in (c) in using the trapezoidal rule to find cl
4. Using the minimum Cp from the last question and Excel
a. Let the minimum Cp from earlier be Cp,0. Use the Prandtl-Glauert rule to plot Cp
from M∞=0 to M∞=0.8 with a maximum interval of ΔM=0.01. Include your name in the
plot title.
b. On the same plot, add the Cp,cr equation from the book and presentation from
M∞=0.4 to M∞=0.8
c. From the plot, what is Mcr and Cp,cr of the airfoil (to the closest 0.01 Mach)?
5. Reduce the magnitude of the minimum Cp from the previous question by 30% (multiply by
0.7). Now use the iterative method to find Mcr and Cp,cr
6. Assume you have a supersonic airfoil at M∞=1.75
a. If the airfoil has the same cl as the one you found in question 3, what is the angle
of attack α in radians and degrees?
b. What is the wave drag coefficient cdw?
The writer is very fast, professional and responded to the review request fast also. Thank you.
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.
Read moreEach paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.
Read moreThanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.
Read moreYour email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.
Read moreBy sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.
Read more