Recent content by caslav.ilic

Just looked in Katz and Plotkin, if you can get a hold of it, the figure 11.27 demonstrates that using a usual first-order, piecewise linear method, with as few as 10 panels in total (5 per side) can give pressure distribution quite reminiscent of an accurate one with 90 panels. -- Chusslove...

Do I understand you correctly: you do not want (are limited, whatever) to use methods which require "big" number of unknowns, so you are searching for a method to give you accurate results with ~20 unknowns along the airfoil contour? If so, I don't think that is possible (according to own...

Depends on the type of wind tunnel. If it's an open test-section tunnel, then, well, the test section is at atmospheric conditions, and static pressure should always be that of room conditions. If the tunnel is with closed test section, then the static pressure will in general vary with...

Depends on what you mean by "theoretical basis". If the flow is assumed inviscid, incompressible, irrotational, i.e. representable by linear potential equation, and the airfoil something akin to a thin plate, then, if I remember correctly, it mathematically drops down to existence of such a...

"Any Fortran software" basically means one needs to have handy: 1) a Fortran compiler (for producing executable program out of written code) 2) a text editor (for writing the code) 3) a command-line shell (for running the compiler and the program) Unfortunately, I cannot tell which...

That does depend on (at least) what is the fluid and the pipe diameter, i.e. Reynolds number. For a nice big Re (all turbulent flow, thin boundary layer) and incompressible fluid, the pressure drop will be linear. That's because the velocity of the fluid will be constant along the pipe (constant...

Just in case the links left by redargon made you draw a conclusion which seems strange, I'll confirm it: you're out of luck as-is. For your application, you must keep the Reynolds number equal to the real world scenario, which means the wind tunnel speed should be not 64/64 = 1, but 64*64 ~ 4000...

(One) point of my arguments was that any computation -- something which has input parameters, number of formulas to process them, and output results -- should be trivially usable at a later point as a part of something that will take 10-20 sec, to hours and days, to compute. And if the...

The expression for drag coefficient looks good. What are your (theta, Cp) values? -- Chusslove Illich (Часлав Илић)

It is not possible to get equation of the form T(p), since p(T) is a complicated enough rational polynomial. Wherever you need to use T(p), you will have to have a numerical solver for it in the background (what those online solvers do). Perphaps Excel has a function for that too? If not, you...

There are degrees of usefulness. Given that spreadsheets are heavily used by engineering community, how could I, or anyone else, present an argument that refutes their utility in total? Is a slide-rule useless, is a hand-held calculator useless? This was not my intention; more specifically, I...

Har, har. Just waited for a mention of that one :) Excel's solver is good, I'll even say "world class", in a certain sense. But there are two crucial problems with it. (Also, make no mistake, CAS tool like Matlab, MathCAD, etc. will contain such solvers without exception. And there are free...

Let's just not confuse counterparts here. From mechanical engineer's viewpoint, MathCAD is to be used in exactly the same capacity as spreadsheet (Excel). There is no reason to use both of them, one "for this" the other "for that". Meaning, of course, that MathCAD is vastly superior to Excel...

Given that -- I suppose -- VBA too can be shown to be Turing complete, you can of course do anything with it (albeit not in practical sense, cf. the questions in my linked message). However, once one has moved to VBA for any decent computation, then he had unwittingly 1) demonstrated that...

This is because I've followed somewhat of an unusual educational path for a mechanical engineer. Other people in my position usually went into fields where spreadsheets are unheard of, as using them would be totally out of question -- so they can't have a strong opinion on something that's...