isothermal choked flow og perfect gas

[sailoday28]

Why in Tech Paper 410 1979 edition pg1-9 is max velocity (following discussion on isothermal flow) described as sound speed? This is upstream of discussion on adiabatic flow.

Will readers think that max exit flow condition for isothermal flow is at Mach = 1?

Regards

 

[MortenA]

Isnt the maximum velocity for a gas the speed of sound at the given process conditions?

Best regards

Morten

 

[sailoday28]

MortenA For the given process"isothermal", the limiting Mach No. at the downstream pipe exit is M=1.
Now M can be greater than one at the pipe inlet, but as you go downstream with the flow, M will decrease.

With subsonic inlet, M will increase towards the exit and the max value is M=1/sqrt(gamma) where gamma is ratio of specific heats.

Similarly for adiabatic flow,with subsonic inlet, M will increase towards exit.- With limiting condition of Mexit=1.