M219 Deep Cavity RMS Pressures on cavity ceiling Pressures in KPa. X/L M=0.6 M=0.85 M=1.35 0.050 0.469 1.053 2.699 0.150 0.462 0.923 1.835 0.250 0.486 1.083 1.590 0.350 0.654 1.366 2.947 0.450 0.897 1.716 4.498 0.550 1.046 2.079 4.742 0.650 1.157 2.318 4.280 0.750 1.489 2.572 3.864 0.850 1.929 3.490 5.724 0.950 2.068 4.117 8.505