Fraser Subsonic Diffuser. Displacement Thickness x (m) del* (m) 1 11 0.1168 0.00134 0.1582 0.00142 0.2106 0.00191 0.2365 0.00248 0.3 0.00381 0.3813 0.00638 0.4384 0.00881 0.4684 0.00975 0.5227 0.01288 0.5776 0.01554 0.6421 0.01895