A concentric tube heat exchanger of length L=2m is used to thermally process a pharmaceutical product flowing at a mean velocity of um. c=0.1 m/s with an inlet temperature of Tc, i=20oC. The inner tube of diameter Di= 10 mm is thin walled, and the exterior tube (Do=20 mm) is well insulated. Water flows in the annular region between the tubes at a mean velocity of um, h=0.2 m/s with an inlet temperature of Th, i=60oC. Properties of the pharmaceutical product are υ=10 X10-6 m2/s, k=0.25 W/mK, rho=1100 kg/m3, and cp=2460 J/kgK. Evaluate water properties at Th= 50oC.

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

An air conditioning system consist of a 5 cm diameter pipe, operating at a pressure of 200 kpa. the air initially enters the pipe at 15°c with a velocity of 20 m/s and relative humidity of 80%. if the heat supply throughout the process is 960 w, determine the relative humidity and the temperature at the outlet

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?