Consider a quasi-steady, turbulent boundary layer on an isothermal flat plate of temperature t the boundary layer is "tripped" at the leading edge (x 0) by a wire. constant physical properties for the fluid in question, the velocity and temperature profiles are found to be of the form: t-too ts-too uoo the shear stress on the plate is related to the boundary layer thickness by an expression of the form: 1/4 0.0228 pu ts beginning with the momentum integral equation (appendix g), show that: 1/5 0.37 6re

On a average work day more than work place firs are reorted

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

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?