Mechanical Engineering - Compressors, Gas Dynamics and Gas Turbines - Discussion

In a centrifugal compressor, the highest Mach number leading to a shock wave in the fluid flow typically occurs at the impeller outlet radius. This is because the impeller is responsible for imparting kinetic energy to the fluid, accelerating it to high velocities.

As the fluid exits the impeller and enters the diffuser, it often experiences a decrease in velocity and an increase in pressure, which can lead to shock waves under certain conditions.

Option d is right, as impeller increases fluid's velocity from impeller inlet to impeller outlet, which is given as (v2) 2- (v1) 2, impeller imparts kinetic energy to fluid thus increases the kinetic energy of the fluid. So, higher kinetic energy of fluid will be at impeller outlet than at impeller inlet.

C is the right answer.

At the impeller inlet radius, The air is deflected through a certain angle before it passes into the radial channel on the impeller vane. If the MACH number at this point exceeds unity shock wave may be formed. The shock wave causes a rapid increase in the losses.

C is the right answer.

At the impeller inlet radius, The air is deflected through a certain angle before it passes into the radial channel on the impeller vane. If the MACH number at this point exceeds unity shock wave may be formed. The shock wave causes a rapid increase in the losses.

The answer should be definitely some inlet as outlets are concerned with H.P. Fluid and thus velocity drop is inevitable there.

Option c should be the right answer.

Option C will be the right answer.

Yes, C will be the right answer.