An airplane flies at a speed of 400 mph at an altitude of 10,000 ft. if the boundary layers on the wing surfaces behave as those on a flat plate, estimate the location on the wing (i. e., the distance x from the leading edge) where the flow transitions to turbulent flow. assume that the critical reynolds number at which the flow transitions from laminar to turbulent flow is given as rexcr=5x105. if the airplane maintains its 400 mph speed by descends to sea level elevation, will the portion of the wing covered by a laminar boundary layer increase or decrease relative to its value at 10,000 ft.? explain!

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

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

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?