What Are Oblique Shock Waves and Expansion Waves?

[fatlady1ac]

Would anybody be able to give me a simple definition on the question below.
Thanks Dylan

 What are oblique shock waves? What are expansion waves?

 

[boneh3ad]

This smells like homework, in which case we are not allowed to answer without you following the guidelines outlined in the homework section and showing that you have at least attempted the problem. Honestly, assuming this is homework, you can find this pretty quickly in your textbook... or on Google.

 

[fatlady1ac]

Its not necessarily homework, however I understand the guide rules, but I agree why it cannot be answered. It is actually a research project which I have to finish as part of my Year 12 which is anoyingly tedious. Anyway I need to have shown evidence that I have asked others for help, and the various people I have tried to talk to in the industry have not replied. Thus I thought I could ask a few questions on PF as part of my communication.
Thanks for the reply anyway I appreciate it.

 

[boneh3ad]

Do you have a compressible flow book handy like Anderson or Oosthuizen (sp)?

 

[35 AoA]

a quick google or wiki search will tell you everything you need to know for casual research on the subject.

 

[fatlady1ac]

Yes I have a book written by John D. Anderson called Fundamentals of Aerodynamics.
From what I have studied is right to assume that a shock wave that occurs at a given angle to the flow is an oblique shock wave, and the fluid in the shock increases in density as it is compressed, resuting in greater pressure and temperature. So the fluid flow speed downstream is less.
Does the above directly increase the drag on an aircraft by converting some of the propulsive (kinetic energy) to thermal energy.
My research is directed into how to the speed of sound increases drag.
Thanks

 

[boneh3ad]

Google wave drag. That ought to give you a little help.

 

[fatlady1ac]

Thanks for all the replies, I have subsequently looked at wave drag and it has been of help.