ECE309 INTRODUCTION TO THERMODYNAMICS & HEAT TRANSFER 16 June 2004 Midterm Examination R. Culham
This is a 90 minute, closed-book examination. You are permitted to use one 8.5 in. 11 in. crib sheet (one side only), Conversion Factors (inside cover of tex
ECE309 Introduction to Thermodynamics and Heat Transfer
Tutorial # 11
Radiation Heat Transfer
Problem 1 Two parallel disks of diameter D=0.6m separated by L=0.4m are located
directly on top of each other. Both disks are black, and are maintained at a temp
Forced Convection
ECE309 Introduction to Thermodynamics and Heat Transfer
Tutorial 9
Question
A truck, pulling a refrigerated trailer, travels at 105
km/hr. Solar radiation heats the roof of the truck, with
the net radiatvie ux being
4
qrad = 375 To
Radia
ECE309 Introduction to Thermodynamics and Heat Transfer
Tutorial # 7
Steady State Conduction
Problem 1
Consider a naked person standing in a room at 20C with an exposed
surface area of 1.7m2. The deep body temperature of the human body is 37C, and the
the
ECE309
Thermodynamics & Heat Transfer
Quiz #1:
Name:
ID #:
Problem: An amusement park at the bottom of Niagara Falls wants to install a
water turbine to produce 100 kW of power. Water (assumed to be incompressible) would enter the pipeline leading to the
ECE309
Thermodynamics & Heat Transfer
Name:
Quiz #3:
ID #:
=1
2.
1
cm
H=
?
W
L=18 cm
Problem: A 12.1 cm wide and 18 cm high vertical
hot surface in 25 C air is to be cooled by an
aluminum heat sink (ks = 177 W/m K) with
equally spaced ns of rectangular pr
ECE 309
Introduction to Thermodynamics and Heat Transfer
Tutorial # 2
Properties of Pure Substances
Problem 1
Complete the following table for substance water:
a.
b.
c.
d.
P [kPa]
500
500
1400
T [oC]
20
v [m3/kg]
x
0.20
200
300
0.8
Solution:
1a.
Step 1: W
ECE309
Thermodynamics & Heat Transfer
Name:
Quiz #2:
ID #:
The composite wall of an oven consists of three materials, two of which are of known thermal conductivity, kA = 20 W/m K and kC = 50 W/m K, and known thickness, LA = 0.30 m and
LC = 0.15 m. The th
ECE309 Introduction to Thermodynamics and Heat Transfer
Tutorial #3
First Law of Thermodynamics: Closed Systems
Problem 3-73 A 0.3-m3 tank contains oxygen initially at 100kPa and 27C. A paddle
wheel within the tank is rotated until the pressure inside ris
Thermodynamics and Heat transfer ECE 309 Tutorial 5# The Second law of Thermodynamics Problem 1 A gas turbine has an efficiency of 17 percent and develops a
power output of 6000 kW . Determine the fuel consumption rate of this gas turbine, in L / min , if
ECE 309
Introduction to Thermodynamics and Heat Transfer
Tutorial # 6
Entropy
Problem 1
Air is compressed steadily by a 5-kW compressor from 100 kPa and 17oC to 600 kPa and
167oC at a rate of 1.6 kg/min. During this process, some heat transfer takes place
ECE 309
Introduction to Thermodynamics and Heat Transfer
Tutorial # 10
Natural Convection
Problem Consider a 15 cm 20 cm printed circuit board (PCB) that has electronic
components on one side. The board is placed in a room at 20oC. The heat loss from the
ECE 309
Heat Transfer & Thermodynamics
Tutorial # 8
Transient Heat Conduction
_
Problem 1: A long aluminium cylinder 50 mm in diameter [k=215 W/(mC), = 2700 kg/m3 ,
Cp = 0.9 kJ/(kgC), and = 8.4 10-5 m2/s] and initially at 200C is suddenly exposed to a
con
ECE-309
Heat Transfer & Thermodynamics
Tutorial # 12
Radiation heat transfer-exchanged between surfaces
Problem 1: A furnace cavity, which is in the form of a cylinder of 75 -mm diameter and 150-mm
length, is open at one end to large surroundin gs that ar