Q.1 / A shaft is loaded in bending and torsion such that M. = 600 lbf. in , T. = 400 lbf. in , Min = 500 lbf in , and Tm = 300 lbfin. For the shaft , S. = 100 kpsi and S , = 80 kpsi, and a fully corrected endurance limit of Se = 30 kpsi is assumed. Let k , = 2.2 and Ks = 1.8 . With a design factor of 2.0 determines the minimum acceptable diameter of the shaft using the (a) DE - Gerber criterion . (b) DE - elliptic criterion. (c) DE - Soderberg criterion. ( d ) DE Goodman criterion . Discuss and compare the results .

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Hydraulic fluid with a sg. of 0.78 is flowing through a 1.5 in. i.d. pipe at 58 gal/min. the fluid has an absolute viscosity of 11.8 x 105 lbf-sec/ft2. is the flow laminar, turbulent or within the critical range? give both a numerical reynolds number and a term answer.

How much power could a wind turbine produce if it had the following specifications? cp = 0.45 -d=1.2kg/m3 d=50m v 5m/s