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LES of shock wave / turbulent boundary layer interaction

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33<br />

extended to the compressible case as:<br />

C finc = F C C f ,<br />

Re θinc = F θ Re θ .<br />

The van-Driest-II transformation for coefficients F C and F θ<br />

with<br />

F C =<br />

α =<br />

F θ = µ ∞<br />

µ w<br />

κ−1<br />

2 M 2 ∞r<br />

(arcsin α + arcsinβ) 2 ,<br />

2A 2 − B<br />

√<br />

4A2 + B 2 ,<br />

β =<br />

A =<br />

B =<br />

B<br />

√<br />

4A2 + B 2 ,<br />

√<br />

κ − 1<br />

(<br />

2<br />

M 2 ∞r T ∞<br />

T w<br />

,<br />

1 + κ − 1 M 2<br />

2<br />

∞r − T )<br />

w T∞<br />

T ∞ T w<br />

is found to be superior to others by Hopkins & Inouye (1971). Here<br />

r = 0.9 is the temperature recovery factor. Obviously, the considered<br />

case (Re δ2 ≈ 2000) is in the region <strong>of</strong> the rapid change <strong>of</strong> C f , where data<br />

are much more scattered than at higher Reynolds number (Re δ2 > 4000).<br />

The calculated skin friction coefficient lies close to the upper limit <strong>of</strong> this<br />

scatter, the referenced experiment at the lower, but both <strong>of</strong> them agree<br />

well with established data from Fernholz & Finley (1977, 1981) and<br />

empirical correlations.<br />

The wall normal distributions <strong>of</strong> mean Mach number, temperature,<br />

velocity, and density are compared with the experimental data in figure<br />

3.4. In the bulk, the computed velocity pr<strong>of</strong>iles agree well with the<br />

experimental data, minor discrepancies can be observed for the density<br />

and temperature pr<strong>of</strong>iles. These differences are well within the experimental<br />

error margin. The computed van-Driest-transformed velocity<br />

pr<strong>of</strong>iles, shown in figure 3.5, agree well with the logarithmic law <strong>of</strong> the<br />

wall U + VD = lnx+ 3 /0.4 + 5.1. Wall-law constants are taken for adiabatic<br />

walls, since our temperature at the wall is equal to the adiabatic one, this

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