Lower critical mach number may be defined as the highest subsonic mach number below which the entire flow over it is subsonic. vijayaprakaash

P. R. Garabedian has written:

'Axially symmetric cavitational flow'

'On subsonic flow of a compressible fluid'

Friedrich Keune has written:

'Low aspect ratio wings with small thickness at zero lift in subsonic and supersonic flow'

'The influence of camber and geometrical twist on low-aspect-ratio wings of finite thickness in subsonic, transonic and supersonic flow'

W. Prichard Jones has written:

'The oscillating aerofoil in subsonic flow'

If the flow is subsonic the pressure will increase, if however it is supersonic the pressure will decrease.