The law in which models are based on Mach number is called as mach model law.

Whenever elastic forces are predominant as compared to other forces, for dynamic similarity, Mach number in the model law must be equal to mach number in the prototype.

M_model = M_prototype

V_m / √ K_m / ρ_m  =  V_p / √K_p / ρ_p

Where   K = Elastic stress

Mach model law are applicable in following cases:

(i)    Flow of aeroplane of supersonic speed
(ii)    Underwater testing of torpedoes.
(iii)    Aerodynamic testing
(iv)    Flow of missiles, rockets.
(v)    Water hammer problem.                                                                     

For more help in Mach Model Law click the button below to submit your homework assignment