d) A 0.3 cm thick aluminum plate (40 W/m. K) has rectangular fins on one side, 0.16 x 0.16 cm, spaced 0. 6 cm apart. The finned side is in contact with air at 38 °C and h = 28.4 W/m2. °C. On unfinned side water flows at 93 °C and h 283.7 W/m2.°C. Calculate (a) efficiency of fins (b) rate of heat transfer per unit area. %D

2. Calculate Passive House's energy demand. a, Calculate window U-value based on given data in figure. 0.117m 0.117m 0.134m C₂ Utotal Wglass-0.996m = 1.229m glass Uglass = 0.6- glass W window - 123m W m².c 0.117m 1.48m nwindow W m² °C Uframe = 1.6- Area₁ U₁ + Area2 U₂... + Area, * U₁ Area total b. With the calculated U value for the windows find out how much power needed to maintain 20°C in a home with outside of 0°C based on the following: the house having a square footprint 17 m by 17 m, walls 2.5 m high (Uwalls = 0.152 each of the four walls hosting two windows, and each window having an area of 2 m². The entry door area is 2.5 m² (Udoor = 0.65- ). What are the heat loss rates for the installed windows, the door, the walls, the ceiling, and the floor? What is the overall heat loss rate of the home? m². C 1. What do these calculated heat loss rate values mean? 2. What is the definition of the passive house? 3. What does the U-value represent? Use its unit as a hint and describe it…

An isothermal long cylinder with square (side of 0.4 m and diagonal of 0.5657 m) cross-section is placed in a flow with a velocity of 1 m/s as shown. The properties of the fluid are: kinematic viscosity is 1.38 x 10-5 m²/s, thermal conductivity is 0.024 W/m.°C, and Prandtl number is 0.73. What is the average Nusselt number for the flow? 1253 a Figure 1: Flow configuration for Problem 6. The dimensions are: a=0.4 m, b=0.5657 m

A steel bar 7 cm long is welded end to end to a copper bar 3 cm long. Each bar has a square cross section 2.00 cm on a side. The free end of the steel with a temprature at 84 °C, and the free end of the cooper bar is at 12 °C. Find the total rate of heat flow in (W)? (ksteel =50.2 W/K.m and kcopper =385 W/K.m ) (Answer in one decimal places) Material having thermal conductivity k Area A T Steel Соpper T,> T,