INCIPIENT shockwave

[osu_jaya]

Hi all....

Am an air craft maintenance student. I have a problem..What is the exact definition of the incipient shock wave... when does it occur ? how can we minimize it??

[TURIN]

There you go..

During earlier research on shock wave/boundary layer interaction control, the effect of air humidity on flow separation has been observed. This has inspired a more detailed study on the effect of air humidity on shock induced incipient separation and on the involved processes. The phenomenon has a twofold nature. In supersonic flow, the condensation of humidity causes flow retardation due to heat addition. The consequent weakening of the shock wave reduces the tendency towards separation. On the other hand, the incipient separation is postponed at the same Mach numbers of interaction.


No, I don't understand it either. :O

[rizwan zain]

regarding my cute little instructor,
shockwave is formed when the local mach number reached mach 1..
another term is when the airflow become supersonic..

[prattgamco]

Usually The Shock Wave Forms When Supersonic Flow Changes Into Subsonic Flow. I.e At Mach 1.but Incipient Shock Wave Starts From M>0.8 To M 1.this Happens When There Is A Sudden Increase Of Pressure And Density,fall In Velocity Over The Aerofoil.u Can See This Wave At The Centre Of The Aerofoil Than The Shock Wave At The 3/4 Of The Aerofoil.

[Genghis the Engineer]

In aerodynamics and aircraft handling, the term "incipient" is used to describe something which is just starting to happen.

So an incipient shockwave is where the first signs of shockwave formation appear, as an aircraft/turbine/wind tunnel accelerates, but before a further increase in airspeed has allowed a clearly defined shockwave to appear.

The quote posted by TURIN is technically correct, but confusing - it mixes up the phenomena of condensation shock and supersonic shock, which are related but technically separate. I'd not worry about it - very few engineers or pilots ever have to know more about condensation shock than that it makes nice photos of F-18s for your screensaver; even for an aerodynamicist it's a pretty obscure subject.

G