Aerodynamics Monographs: Recent Advances in High Mach Subsonic Flight

[rhb]

Summary:: I'm looking for recommendations of recent aerodynamics monographs which treat high Mach number subsonic (pre-transsonic) flight thoroughly.

I'm looking for recommendations of recent aerodynamics monographs which treat high Mach number subsonic (pre-transsonic) flight thoroughly. I am particularly interested in concepts such as "equal area" for increasing the velocity without a significant drag penalty as one gets close to the transsonic region.

I want to get 2-3 monographs which have come out in the last 10 years, though older work still of interest. I'm a retired research scientist/programmer with a 5000+ volume technical library. If I get curious about something I buy some graduate level books and read them. Finding the right books in a new area is sometimes difficult.

I've got many of the aerodynamics classics, but no recent monographs. I'm skittish about buying some of the classics because I'm not sure if I have a copy or not until I straighten up my library.

I'm particularly interested in a modern discussion of the NACA 6 series airfoil performance relative to CFD optimizations. Come to think of it, I'd also like to get some books on aeroelastic CFD. I'm already reasonably familiar with liquid phase CFD in porous media. But gas phase is rather different.

Have Fun!
Reg

 

[sysprog]

What do you mean by "high Mach number subsonic (pre-transsonic) flight"? $-$ isn't a Mach number greater than 1 already supersonic?

 

[rhb]

"High Mach number" is < 1.0 for subsonic. This is how it was described in the half dozen or so aerodynamics books I have. I'm not an aerodynamicist, but I am a research scientist, so I "go with the flow" when I wander into something I know very little about beyond basics physics.

Every wing profile has a speed at which the drag increases. The air velocity at which the drag increases is very important if you want high speed and fuel efficiency. As it happened, the WW II 6x series NACA airfoils were especially good at raising the speed at which drag increased. Thereby allowing faster planes for the same power input.

BTW Books *not to buy* with an explanation of why would be equally welcome.

 

[sysprog]

I've seen some articles that call 0.75 M a high Mach number, but I don't aee any reasoning behind that designation that I find compelling $-$ it looks like a convention in aerodynamics parlance due to common airspeeds being subsonic.

 

[boneh3ad]

I've seen some articles that call 0.75 M a high Mach number, but I don't aee any reasoning behind that designation that I find compelling $-$ it looks like a convention in aerodynamics parlance due to common airspeeds being subsonic.

It's not, but you can go ahead and make whatever wild assumptions you'd like. It's actually a pretty well established answer, although the selection of 0.75 is sort of a "good place to start" rather than a hard rule. In transonic flows, there is a term called the critical Mach number, which is the free-stream Mach number at which the flow reaching $M=1$ somewhere on the airfoil. There is also a slightly higher (though similar) Mach number at which the drag coefficient suddenly and rapidly increases as wave drag becomes important due to local supersonic regions of the flow. This is called the drag-divergence Mach number. The selection of $M=0.75$ just represents a convenient Mach number below which these transonic effects have not yet occurred, but again, it's application-specific. You could see it occurring all the way down to $M\approx 0.6$ or up to $M\approx 0.8$ depending on the airfoil section.

@rhb
Ultimately, a textbook/monograph on high-subsonic flow may not really exist. The regime is pretty well covered by any standard compressible flow text, as it obeys more or less the same equations as supersonic flow. The main difference is just that the equations are hyperbolic for supersonic flows and elliptic for subsonic flows, so the behavior is different despite the similarity in governing equations.

 

[FactChecker]

This sounds like the type of thing where you might have to go to an Aerodynamics Engineering school library and do a literature search. I am not aware of any change in the theory (or reality) as long as it stays below transonic. But I am not an expert in this subject and must leave it for others to answer.

 

[Klystron]

The OP mentions NASA predecessor NACA publications. NASA research centers that specialize in aerodynamics including Ames, Langeley, Edwards and Huntsville maintain extensive libraries with most unclassified non-proprietary publications open to fellow professionals. Wind tunnel and true flight experiment results list by date, location, requesting org, authors and aircraft platform or part being tested.

I learned beaucoup aerodynamics and space science by studying in Ames libraries, then mainly paper. Try accessing NASA's online free information portal for your region; a university or laboratory affiliation helps but should not be essential.

 

[rhb]

@boneh3ad: Thanks for the spot on summary.

@FactChecker: Going to a library would cost more than buying several books :-(

@Klystron: I've downloaded a fair bit of the NACA publications already and will collect the rest in time.

My most recent text is:

"Fundamentals of Aerodynamics"
John D. Anderson, Jr.
McGraw-Hill 1984 1st ed.

The 6th ed. came out in 2016 and is 1152 pages which is more than twice as long as the 1st ed. As all the editions get high marks I'm going to get a copy of that for a start and then pick up some of the references he cites.

I'm continually amused by the textbook rental racket. I can't imagine taking someone who didn't own a copy of the text they used for such a course seriously. Owning the book is negligible relative to the cost of taking the course.

 

[boneh3ad]

@boneh3ad: Thanks for the spot on summary.

@FactChecker: Going to a library would cost more than buying several books :-(

@Klystron: I've downloaded a fair bit of the NACA publications already and will collect the rest in time.

My most recent text is:

"Fundamentals of Aerodynamics"
John D. Anderson, Jr.
McGraw-Hill 1984 1st ed.

The 6th ed. came out in 2016 and is 1152 pages which is more than twice as long as the 1st ed. As all the editions get high marks I'm going to get a copy of that for a start and then pick up some of the references he cites.

I'm continually amused by the textbook rental racket. I can't imagine taking someone who didn't own a copy of the text they used for such a course seriously. Owning the book is negligible relative to the cost of taking the course.

That's definitely a good place to start. Anderson also has a compressible flow text with a lot of good stuff in it: Modern Compressible Flow with Historical Perspective. You probably already have it, but the classic Elements of Gasdynamics by Liepmann and Roshko is a real gem and is only like $14 on Amazon.