An airplane flies at a speed of 539 mph at an altitude of 10,000 ft. If the boundary layers on the wing surfaces behave as those on a flat plate, (a) estimate the extent of laminar boundary layer flow along the wing. Assume a transitional Reynolds number of Rexcr = 5 x 105. If the airplane maintains its 539 -mph speed but descends to sea-level elevation, (b) estimate the extent of the laminar boundary layer flow. (c) Will the portion of the wing covered by a laminar boundary layer increase or decrease compared with its value at 10,000 ft?

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

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?

True or false (explain) (110)[111] is a slip system in bcc metals . the {111} family in fcc contains 8 planes. resolved shear stress (rss) in single crystals is just related to the applied stress. critical resolved shear stress (crss) in single crystal metals is direct proportional to the number of defects in the structure