Estimate the unit thermal resistance for a vertical 1.5 in. (40 mm) air space. The air space is near the inside surface of a wall of a heated space that has a large thermal resistance near the outside surface. The outdoor temperature is 10 F (-12 C). Assume nonreflective surfaces.

Estimate the unit thermal resistance for a vertical 1.5 in. (40 mm) air space. The air space is near the inside surface of a wall of a heated space that has a large thermal resistance near the outside surface. The outdoor temperature is 10 F (-12 C). Assume nonreflective surfaces.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.4P: 1.4 To measure thermal conductivity, two similar 1-cm-thick specimens are placed in the apparatus...

See similar textbooks

Related questions

Q: 9-29 The permissible shear stress for the weldment illustrated is 140 MPa. Estimate the load, F,…

A: Given Dataτs=140Mpad=75mms=6mm

Q: Design the diameter of a steel pipe to carry water having kinematic viscosity v=10 m²/s with a mean…

A: Given: Let us consider the given data, ν=10-6 m2shL=5 mL=100 mks=45×10-4 cmV=1 ms Darey-Weisbach…

Q: Two rigid tanks are connected by a valve. The left tank is filled with 8.6 ft of air initially at 22…

A: Given Pressure, PA = 22 psia PB = 17.3 psia Volume, VA = 8.6 ft3 VB =…

Q: A projectile is launched with a speed vo= 29 m/s from the floor of a 4-m-high tunnel as shown.…

Q: Water contained in a piston-cylinder assembly, initially at 300°F, a quality of 70%, and a volume of…

Q: Five lbs of propane is contained in a closed, rigid tank initially at 80 lbf/in.², 150°F. Heat…

Q: Question 16 If the stroke volume of engine = 300 cc, and clearence volume of engine = 20 cc, the…

A: Option d is correct.

Q: ressurea are sometimes determined by measuring the height of a column of liquid in a vertical tube,…

A: Given Temperature, T = 20oC Height, h = 1 mm Find Diameter, d

Q: Determine the volume change, in ft3, when 1 lb of water, initially saturated liquid, is heated to…

A: Given:- Mass of water (m) = 1 lbsaturated liquid is being heated to saturated vapor at constant…

Q: Locate all the instantaneous centres of the mechanism as shown in Fig. 6.29. The lengths of various…

A: Given DataN=240 rpmAB=150mm=0.15mBC=300 mm=0.3mCD=225mm=0.225mCE=500mm=0.5m

Q: A steel bolt 25 mm in diameter carries a load of 4 kN in tension. Estimate the tensile stress of the…

A: Given data Load= 4 kn Diameter of bolt = 25 mm Diameter of thread = 20 mm Find the tensile stress at…

Q: 5 A cylindrical workpiece is forged in an open die. The workpiece is 60 mm in diameter and 30 mm…

Q: 21 k (i) его m 9 Let the position vector for m have the form A particle of mass m is suspended by a…

A: Given: To find: Expression for kinetic and potential energy Approximation for potential energy…

Q: What is the equivalent mass flow rate ( kg/hr ) of water delivered at 250 gpm. Water is delivered at…

A: GivenPart 1Q˙=250 gpm m˙= ? kg/hr

Q: A material presents S-N fatigue behaviour shown on the right with the fatigue limit being 100 MPa.…

A: Given data: Se= 100 MPa. Diameter of the bar d= 20 mm. To ensure no occurance of the fatigue…

Q: 9. Derive the transfer function X₂(s)/F(s) for the mechanical system shown in Figure 2. Assume the…

A: Given Data: Mechanical system with a properties are M1 = 3 kg, M2 = 2 kg, K1 = 5 N/m, K2 = 3 N/m, D1…

Q: As shown in the figure below, a cylinder fitted with a piston is filled with 700 lb of saturated…

A: Mass of ammonia = 700 lb Temperature = 45 °F Piston weight = 1 ton Diameter = 2.5 ft Find the…

Q: 3.13 A house has a composite wall of wood, fiberglass insula- tion, and plaster board, as indicated…

Q: A temperature sensor may be modeled as a sphere having a thermal conductivity of 91 W/m-K, a density…

Q: uch that the horizontal welds are b, and by long. Determine F if th ress is allow P₁ b₂ dh Tallow mm…

A: Thickness, h =5 mmWelds, b1 = 30 mm, b2 = 50 mmd = 50mmζallow = 140 MPa To-Determine:- Force F

Q: 4. The inner wall of a thermos bottle is at 32°F while the outer at 102.0°F. The space between the…

Q: Steam, initially at 700 lbf/in.2, 550°F undergoes a polytropic process in a piston-cylinder assembly…

Q: A cone clutch with a cone semi-angle of 120 is to transmit 11.19KW at 750rpm. The width of the face…

Q: company has several sensors in storage silos to detect the total pressure in the silos to ensure the…

A: Given Pressure, P = 5.8 atm Density = 97 lbm/ft3 = 1541 kg/m3 Height, h = 80 ft = 27.43…

Q: Room walls are composed of common bricks and outside and inside plaster layers with an overall heat…

Q: 3.5 A dormitory at a large university, built 50 years ago, has exterior walls constructed of L, =…

A: Given data Ls = 25 mm Ks = 0.1 W/mk Li = 25 mm Ki = 0.029 W/mk Lg= 5 mm Kg = 1.4 W/mk Ti = 22°C ,…

Q: 8. Derive the transfer function X₁ (s)/F(s) for the mechanical system shown in Assume the following…

Q: Question 1 You are working on a design team at a small orthopaedic firm. You have been asked to…

Q: A canal of trapezoidal section has bed width of 8 m and bed slope of 1 in 4000. If the depth of flow…

Q: A particle moves along a path according to the equations x = 9 - +4/9 and y = +²/3 where x and y are…

A: Given Data- Particle moving along x and y direction x=9-t49 y=t23 We have to find acceleration of…

Q: Assuming f-0.020, determine the discharge in the pipes. Neglect minor losses. Pipe Diameter AB BC BD…

A: f = friction factor = 0.020 LAB = 1200 m, dAB = 250 mm LBC = 600 m, dBC = 200 mm LBD = 800 m, dBD =…

Q: For continuous and aligned fibre composites, prove that the Young's modulus of the composites along…

A: Ec = youngs modulus of composite Em = youngs modulus for matrix Ef = youngs modulus for fiber Vm =…

Q: Air is compressed in a piston-cylinder assembly from p₁ = 25 lb/in², T₁ = 500°R, V₁ = 9 ft³ to a…

Q: 6-47E A heat pump with a COP of 1.4 is to produce 100,000 Btu/h heating effect. How much power does…

A: Disclaimer: Since you have asked multiple question, we will solve the first question for you. If you…

Q: A rocket, fired from rest at time t = 0, has an initial mass of m0 (including its fuel). Assuming…

Q: The water flows to the nozzle through a 180-degree elbow. The pipe diameter D-75mm, the nozzle…

Q: A simple ideal Rankine cycle with water as the working fluid operates between the pressure limits of…

A: Given data: Cycle : Simple Rankine cycle Turbine inlet pressure = P1 = 10 MPa Turbine inlet…

Q: Solve the given beam below, determine the maximum moment.

Q: A hollow circular shaft has an outer diameter of 100 mm and a wall thickness of 25 mm. The allowable…

A: Introduction The generalized torsional…

Q: Because you forgot to let the pipes drip during a freezing night, a section of an outdoor pipe is…

Q: What is the difference between petrol engine and Diesel engine?

A: petrol engine- In this type of engine spark is provided for burning of fuel. Diesel engine-In this…

Q: The figure above shows a schematic of a gas turbine engine. Engines such as these provide thrust to…

A: Given questions are related to machine design, material science and manufacturing engineering.

Q: Given the cable tension T = 80 lb, determine a) the moment about point A due to T, and b) the…

A: Given Tension, T = 80 lb Distance, AB = 32 in Find Moment, A Shortest distance x

Q: If FB = 830 N, Fc = 450 N, determine the magnitude of the resultant force at A. (Figu Express your…

A: Given FB=830NFC=450N

Q: Shifting from second to third gear in a car is an example of which type of motor skill? Question 4…

A: Explanation: Open Motor skill: it involves the motion of supporting surfaces, objects, or people in…

Q: A projectile is launched with a speed vo = 20.8 m/s from the floor of a 4.2-m-high tunnel as shown.…

Q: A room being air conditioned is held at 25°C db & 50% RH. A flow rate of 5m³/s of supply air at 15°C…

A: Given data P=100 kPaV1=5 m3/sT1=15°C Here, P is the pressure and V1 is the volume of the air flow.…

Q: A 5-kN tensile load is applied to a test coupon made from 1.6-mm flat steel plate (E = 200 GPa, v =…

Q: A compressor is to be used to draw air from the outdoors where the conditions are 26.5 C and 100.04…

A: The given information in the problem is listed in the following attached image:

Q: The bracket which is fastened to a wall by anchor bolts at A and B is loaded by the forces P=120N…

A: Given data: P=120 N C=140 N-m

Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.

Question

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step by step

Solved in 2 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

Similar questions

1.2 The weight of the insulation in a spacecraft may be more important than the space required. Show analytically that the lightest insulation for a plane wall with a specified thermal resistance is the insulation that has the smallest product of density times thermal conductivity.
1.4 To measure thermal conductivity, two similar 1-cm-thick specimens are placed in the apparatus shown in the accompanying sketch. Electric current is supplied to the guard heater, and a wattmeter shows that the power dissipation is 10 W. Thermocouples attached to the warmer and to the cooler surfaces show temperatures of 322 and 300 K, respectively. Calculate the thermal conductivity of the material at the mean temperature in W/m K. Problem 1.4
As a designer working for a major electric appliance manufacturer, you are required to estimate the amount of fiberglass insulation packing (k = 0.035 W/m K) that is needed for a kitchen oven shown in the figure below. The fiberglass layer is to be sandwiched between a 2-mm-thick aluminum cladding plate on the outside and a 5-mm-thick stainless steel plate on the inside that forms the core of the oven. The insulation thickness is such that the outside cladding temperature does not exceed 40C when the temperature at the inside surface of the oven is 300C. Also, the air temperature in the kitchen varies from 15Cto33C, and the average heat transfer coefficient between the outer surface of the oven and air is estimated to be 12.0W/m2K. Determine the thickness of the fiberglass insulation that is required for these conditions. What would be the outer surface temperature when the inside surface of the oven is at 475C?
1.10 A heat flux meter at the outer (cold) wall of a concrete building indicates that the heat loss through a wall of 10-cm thickness is . If a thermocouple at the inner surface of the wall indicates a temperature of 22°C while another at the outer surface shows 6°C, calculate the thermal conductivity of the concrete and compare your result with the value in Appendix 2, Table 11.
Wearing layers of clothing in cold weather is often recommended because dead-air spaces between the layers keep the body warm. The explanation for this is that the heat loss from the body is less. Compare the rate of heat loss for a single 2-cm-thick layer of wool [k=0.04W/(mK)] with three 0.67-cm layers separated by 1.5 mm air gaps. The thermal conductivity of air is 0.024 W(mK).
A person wearing a heavy parka is standing in a cold wind. Describe the modes of heat transfer determining heart loss from the person's body.
One end of a 0.3-m-long steel rod is connected to a wall at 204C. The other end is connected to a wall that is maintained at 93C. Air is blown across the rod so that a heat transfer coefficient of 17W/m2 K is maintained over the entire surface. If the diameter of the rod is 5 cm and the temperature of the air is 38C, what is the net rate of heat loss to the air?
1.37 Mild steel nails were driven through a solid wood wall consisting of two layers, each 2.5-cm thick, for reinforcement. If the total cross-sectional area of the nails is 0.5% of the wall area, determine the unit thermal conductance of the composite wall and the percent of the total heat flow that passes through the nails when the temperature difference across the wall is 25°C. Neglect contact resistance between the wood layers.
1.3 A furnace wall is to be constructed of brick having standard dimensions of Two kinds of material are available. One has a maximum usable temperature of 1040°C and a thermal conductivity of 1.7 W/(m K), and the other has a maximum temperature limit of 870°C and a thermal conductivity of 0.85 W/(m K). The bricks have the same cost and are laid in any manner, but we wish to design the most economical wall for a furnace with a temperature of 1040°C on the hot side and 200°C on the cold side. If the maximum amount of heat transfer permissible is 950 , determine the most economical arrangement using the available bricks.
1.1 On a cold winter day, the outer surface of a 0.2-m-thick concrete wall of a warehouse is exposed to temperature of –5°C, while the inner surface is kept at 20°C. The thermal conductivity of the concrete is 1.2 W/m K. Determine the heat loss through the wall, which is 10-m long and 3-m high. Problem 1.1
1.63 Liquid oxygen (LOX) for the space shuttle is stored at 90 K prior to launch in a spherical container 4 m in diameter. To reduce the loss of oxygen, the sphere is insulated with superinsulation developed at the U.S. National Institute of Standards and Technology's Cryogenic Division; the superinsulation has an effective thermal conductivity of 0.00012 W/m K. If the outside temperature is on the average and the LOX has a heat of vaporization of 213 J/g, calculate the thickness of insulation required to keep the LOX evaporation rate below 200 g/h.
2.30 An electrical heater capable of generating 10,000 W is to be designed. The heating element is to be a stainless steel wire having an electrical resistivity of ohm-centimeter. The operating temperature of the stainless steel is to be no more than 1260°C. The heat transfer coefficient at the outer surface is expected to be no less than in a medium whose maximum temperature is 93°C. A transformer capable of delivering current at 9 and 12 V is available. Determine a suitable size for the wire, the current required, and discuss what effect a reduction in the heat transfer coefficient would have. (Hint: Demonstrate first that the temperature drop between the center and the surface of the wire is independent of the wire diameter, and determine its value.)