Air enters a duct at 700 kPa and Ma = 0.05. The duct has a wetted perimeter of 1 m and a flow area of 0.1 m 2 . Find the air pressure at a length of 150 m from the pipe entrance. The air temperature...

Air enters a duct at 700 kPa and Ma = 0.05. The duct has a wetted perimeter of 1 m and a flow area of 0.1 m². Find the air pressure at a length of 150 m from the pipe entrance. The air temperature remains constant in the pipe.

Air flows in a pipeline at a rate of 25 kg/s. The pipe is 1000 m long and has an inside diameter of 0.35 m. Assuming isothermal process, find the pipe length over which the flow remains subsonic. Data:
P_i


= 0.5 MPa,
T_i

= 27 C,
f
= 0.015.