Engineering, 21.01.2021 22:30 simrankaurdhatt
An electric heater is embedded in a long cylinder of diameter 30 mm. When water with a temperature of 25 deg C and velocity 1m/s flows over it the power per unit length required to maintain the surface at a uniform temperature of 90 deg C is 28 kW/m. When air, also at 25 deg C, flows over it at 10 m/s, the power required to maintain the same surface temperature is 400W/m. Calculate and compare the convection coefficients for the flow of water and air. [Hint: The water is flowing over the cylinder and therefore, heat transfer is through the surface of the cylinder, not the cross-sectional area. So you need to find the appropriate area per unit length]
Answers: 3
Engineering, 03.07.2019 15:10
Two flowing streams of argon gas are adiabatically mixed to form a single flow/stream. one stream is 1.5 kg/s at 400 kpa and 200 c while the second stream is 2kg/s at 500 kpa and 100 ? . it is stated that the exit state of the mixed single flow of argon gas is 150 c and 300 kpa. assuming there is no work output or input during the mixing process, does this process violate either the first or the second law or both? explain and state all your assumptions.
Answers: 1
Engineering, 04.07.2019 18:10
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Engineering, 04.07.2019 18:10
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.
Answers: 3
Engineering, 04.07.2019 18:10
Which one from below is not one of the reasons of planning failures? (clo3) a)-planner is careless. b-planner spend less time in the field but more time on the desk c)-planner is not qualified d)-planner does not have sufficient time to properly plan
Answers: 3
An electric heater is embedded in a long cylinder of diameter 30 mm. When water with a temperature o...
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