Ahelium compressor the relative mach number is mr/s=0.85 at the shroud of the impeller. the inlet stagnation pressure and temperature are 101.325 kpa and 288 k. the mass flow rate is 1.8 kg/s. the hub- to-shroud radius ratio is 0.38, and the inlet flow is axial. determine; (a) the rotational speed of the impeller, (b) the axial velocity, and (c) the inducer shroud diameter, assuming that the inducer is designed for optimum relative flow angle, and that the compressor operates at the design point.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Compute the pressure drop of 30°c air flowing with a mean velocity of 8 m/s in a circular sheet-metal duct 300 mm in diameter and 15 m long. use a friction factor, f 0.02, and pair = 1.1644 kg/m a. 37.26 pa b. 25.27 pa n c. 29.34 pa d. 30.52 pa

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?