3.8 Determine (i) the pressure drop, and (ii) the convective heat transfer coefficient from hot air ( Tin = 500 K, Pin = 101.3 kPa, m = 3.5 kg/s) to a cold-packed bed of spheres (L vessel = 6.0 m, D vessel = 1.50 m, D = 300 K, c sphere = 0.8 kJ/kgK, k sphere init = 1.05 W/mK). = 3.8 cm, o = 0.45, T sphere Answer. (a) Ap = 9.46 kPa ; (b) h = 115

A shell-and-tube heat exchanger is used to cool compressed liquid methanol from 176 °F to 104 °F. The methanol flows on the shell side of the exchanger. The coolant is water that rises in temperature from 50 °F to 86 °F and flows within the tubes at a rate of 68.9 kg s1. Finding the appropriate thermophysical data and applying the proper equations, you are required to do the following: (a) Calculate i) methanol mass flow rate in the exchanger, ii) methanol volumetric flowrate at the inlet of the exchanger. (b) i) For the counter-current flow of the fluids calculate the log temperature difference, ii) explain the purpose of calculating this difference, iii) explain, quantitatively, why is the counter-current flow in heat exchangers preferred to co-current flow. mean

You are designing a pin-style heatsink for forced cooling of an IC. A small fan blows RT air into the heatsink at about 2.3 ? ? . The aluminum pins are 2mm in diameter and have a constant surface temperature of 120°?. The heatsink is 100mm x 100mm and the pins have an inline arrangement with a transverse pitch of 4mm and a longitudinal pitch of 6mm. What is the total heat dissipation of this heatsink? The pins are 30mm high. Note RT=25 celsius

A 2 m wide, 3 m high, and 50 mm thick sheet of XPS insulation (M = 50 ng/Pa.s.m2), has a vapor pressure of 1500 Pa on one side, and 3500 Pa on the other. Calculate the vapor flow rate (Qv), vapor flux (qv), permeability, Rv value and the permeability (μ)