QUESTION 2The wall of a refrigerated truck consists of 1.5mm sheet steelouter surface, 10mm plywood at the inner surface and 20mmof glass wool in between. The inside temperature is -15°Cand outside temperature is 240C. Take the thermalconductivities of the materials as follows: -0,052W/mK= 23,2W/mKk for glass-wool = 0,14W/mKk for plywoodk for steel%3D%3D%3DCalculate:2.1. the rate of heat flow per unit area;2.2. the interface temperature.If the glass-wool is replaced by a 5mm cork board with athermal conductivity of 0.043W/mK;2.3. What percentage change in heat flow is obtained?2.4. What must be the thickness of the cork board be, toachieve the same heat flow as in (2.1.).

Answered: Image /qna-images/answer/7205cb3f-8e8d-460b-99ff-43590645e089.jpg

The wall of a refrigerated truck consists of 1.5mm sheet steel outer surface, 10mm plywood at the inner surface and 20mm of glass wool in between. The inside temperature is -15°C and outside temperature is 24°C. Take the thermal conductivities of the materials as follows: - 0,052W/mK = 23,2W/mK k for glass-wool = 0,14W/mK k for plywood k for steel %3D %3D Calculate: 2.1. the rate of heat flow per unit area; 2.2. the interface temperature. If the glass-wool is replaced by a 5mm cork board with a thermal conductivity of 0.043W/mK; 2.3. What percentage change in heat flow is obtained? 2.4. What must be the thickness of the cork board be, to achieve the same heat flow as in (2.1.).

The wall of a refrigerated truck consists of 1.5mm sheet steel outer surface, 10mm plywood at the inner surface and 20mm of glass wool in between. The inside temperature is -15°C and outside temperature is 24°C. Take the thermal conductivities of the materials as follows: - 0,052W/mK = 23,2W/mK k for glass-wool = 0,14W/mK k for plywood k for steel %3D %3D Calculate: 2.1. the rate of heat flow per unit area; 2.2. the interface temperature. If the glass-wool is replaced by a 5mm cork board with a thermal conductivity of 0.043W/mK; 2.3. What percentage change in heat flow is obtained? 2.4. What must be the thickness of the cork board be, to achieve the same heat flow as in (2.1.).

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Related questions

Q: that heat loSs only occurs through the window, calculate w Ece to maintain the temperature, if the…

Q: W concrete on the outside is 8.00cm thick and has a thermal conductivity of 0.500- m.K W wood on the…

A: givenoutside temp= 7.00°cinside temp=22.00°csurface area of wall= 20.0m3

Q: Two walls of a stol composed of insulating materia (k=0.25 KJ/hr-m-°C) with 15 cm thick and concrete…

A: Given For insulating material Thermal conductivity, k1 = 0.25 kJ/hr.m.K…

Q: The walls of the flat furnace are connected by two insulating layers A and B. The temperature of the…

Q: Problem 3: The composite wall shown in the figure below is 200mm H x 100mm wide. What is the…

A: Let T1 be the temperature between the adiabatic wall and G10 fiberglass, T2 be the temperature…

Q: Electrical current flows through a cylindrical cable with a diameter of d = 4 mm generating thermal…

Q: A thick-walled tube of stainless steel with thermal conductivity k = 19 W/m°C has inner diameter of…

Q: Adiabatic Wall Steel 5mm T. = 25°C W h = 45 m²K Aluminum G10 Aluminum 16mm %3D Steel 5mm 6mm 8mm 4mm

Q: A pipe of length L connects to thermal reservoirs that are kept constant at temperatures T₁ and T₂.…

A: GivenReservoirs temeprature T1 and T2length of the pipe =Lx=0.2L

Q: Consider a composite wall of overall height H = 30 mm and thickness L = 40 mm. Section A has…

Q: Consider a multi-layered walls of a storage building (no windows) that is made of three layers as…

A: a) The thermal resistance diagram is given below- T1 = Inside temperature of the wallT2 =Temperature…

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 3

VIEW

Step by step

Solved in 3 steps with 3 images

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

Please include a fbd of the problem
1) A wall section composed from the outside to inside, of concrete brick 100mm thick, an air space of 50mm, two layers of fiberglass insulation 38mm thick, concrete block 150mm thick and air space of 19mm and a gypsum board of 13mm. The exterior conditions are -20C and RH=90% while the interior conditions are 23C and RH=40%. The surface temperature from the outside to inside are shown in the figure. The permeances are: Still Air: µ = 175 ng/pa.s.m Fiber glass: M=2560 ng/pa.s.m? Concrete block: M= 200 ng/pa.s.m? Gypsum board: M= 2000 ng/pa.s.m? Concrete brick: µ = 4.55 ng/pa.s.m Determine if there is a risk of condensation, and if there is, what is the condensation rate? What would happen if a vapor barrier (M=0.2 ng/pa.s.m²) was installed on the warm side of the insulation (Surface 4). 21с 19C 16 С 12C -10 -15C -18C -19C Gyp Air Concrete Fiber Fiber Air Concrete Outdoor Indoor sum block Glass Glass brick 230 19 50 mm -20C 13 150 mm 38 mm | 38 mm 100 mm RH=90% RH=40% mm mm Surf. 1 Surf.…
Consider a power transistor encapsulated in an aluminum case that is attached at its base to a square aluminum plate of thermal conductivity k= 240W/m.K, thickness L= 6mm, and width W= 20mm. The case is joined to the plate by screws that maintain a contact pressure of 1 bar, and the back surface of the plate transfers heat by natural convection and radiation to ambient air and large surroundings at T∞ =Tsur -25°C. The surface has an emissivity of ε=0.9, and the convection coefficient is h=4 W/m².K. The case is completely enclosed such that heat transfer may be assumed to occur exclusively through the base plate. a) If the air-filled aluminum-to-aluminum interface is characterized by an area of A₁=2×10-4 m² and contact resistance of R+c= 1.375 K/W, what is the maximum allowable power dissipation if the surface temperature of the case, Ts,c, is not to exceed 85°C? S,C' Transistor case Ts. Pelec S,C' Enclosure W Isur Base plate, (k,ε) Interface, Ac Air Th 801 b) How much should the h be…
A square steel bar of side length w = 0.21 m has a thermal conductivity of k = 15.6 J/(s⋅m⋅°C) and is L = 2.7 m long. One end is placed near a blowtorch so that the temperature is T1 = 95° C while the other end rests on a block of ice so that the temperature is a constant T2. a. input an expression for the heat transferred to the cold end of the bar as a function of time using A=w^2 as the cross-sectional area of the bar. b. how much energy in joules was conducted in 1 hour, assuming t2=0*C c. input an expression for the mass of the water melted in one hour using Q1 from above and Lf in the latent heat of fusion. mw=