Steady blowing/suction

A very simple approach of flow control is steady suction and blowing. First this kind of excitation is investigated and results are summarised in Tab. 1. The intensity is $C_{\mu}$ = $100 \cdot 10^{-5}$ in both cases.

Case	mean	mean	flow	dominant
	lift	drag	sep.	frequency
	$c_{l,mean}$	$c_{d,mean}$	$x_d/c_k$	$F^+$
without Exc.	2.686	0.201	$4.4\%$	0.442
st. suction	2.742	0.170	$14.6\%$	0.528
st. blowing	2.630	0.198	$3.6\%$	0.420

Tab. 1 $\$ Results of steady suction and blowing

The results indicate, that only steady suction is effective. Flap separation can be delayed and the mean lift increases by $2\%$ while the drag drops. It is also remarkable that the frequency of detaching vorticies significantly increases from $F^+=0.442$ in the baseline simulation to $F^+=0.528$ for steady suction. Steady blowing does not give any positive effect.