Which option shows the most valuable metallic properties

A plane wall of thickness 0.1 m and thermal conductivity 25 W/m·K having uniform volumetric heat generation of 0.3 MW/m3 is insu

Contact [7]

Answer:

T = 167 ° C

Explanation:

To solve the question we have the following known variables

Type of surface = plane wall ,

Thermal conductivity k = 25.0 W/m·K,

Thickness L = 0.1 m,

Heat generation rate q' = 0.300 MW/m³,

Heat transfer coefficient hc = 400 W/m² ·K,

Ambient temperature T∞ = 32.0 °C

We are to determine the maximum temperature in the wall

Assumptions for the calculation are as follows

Negligible heat loss through the insulation
Steady state system
One dimensional conduction across the wall

Therefore by the one dimensional conduction equation we have

$k\frac{d^{2}T }{dx^{2} } +q'_{G} = \rho c\frac{dT}{dt}$

During steady state

$\frac{dT}{dt}$ = 0 which gives $k\frac{d^{2}T }{dx^{2} } +q'_{G} = 0$

From which we have $\frac{d^{2}T }{dx^{2} } = -\frac{q'_{G}}{k}$

Considering the boundary condition at x =0 where there is no heat loss

$\frac{dT}{dt}$ = 0 also at the other end of the plane wall we have

$-k\frac{dT }{dx } =$ hc (T - T∞) at point x = L

Integrating the equation we have

$\frac{dT }{dx } = \frac{q'_{G}}{k} x+ C_{1}$ from which C₁ is evaluated from the first boundary condition thus

0 = $\frac{q'_{G}}{k} (0)+ C_{1}$ from which C₁ = 0

From the second integration we have

$T = -\frac{q'_{G}}{2k} x^{2} + C_{2}$

From which we can solve for C₂ by substituting the T and the first derivative into the second boundary condition s follows

$-k\frac{q'_{G}L}{k} = h_{c}( -\frac{q'_{G}L^{2} }{k} + C_{2}-T∞)$ → C₂ = $q'_{G}L(\frac{1}{h_{c} }+ \frac{L}{2k} } )+T∞$

T(x) = $\frac{q'_{G}}{2k} x^{2} + q'_{G}L(\frac{1}{h_{c} }+ \frac{L}{2k} } )+T∞$ and T(x) = T∞ + $\frac{q'_{G}}{2k} (L^{2}+(\frac{2kL}{h_{c} }} )-x^{2} )$

∴ Tmax → when x = 0 = T∞ + $\frac{q'_{G}}{2k} (L^{2}+(\frac{2kL}{h_{c} }} ))$

Substituting the values we get

T = 167 ° C

4 0

4 years ago

A keyboard, monitor and mouse are all considered as computer hardware and a program is known as a software.

Iteru [2.4K]

Answer:

This should be true because program is a software and mouse and keyboard are specific computer hardware to make your exsperience with a computer more efficent and faster.

5 0

3 years ago

The modifications of superheat and reheat for a vapor power plant are specifically better for the operation which of the followi

MatroZZZ [7]

The modifications of superheating and reheat for a vapor power plant are specifically better for the operation which of the following components b.Boiler.

<h3>What are the primary additives in the vapour strength cycle?</h3>

There are 5 steam strength cycles: The Carnot cycle, the easy Rankine cycle, the Rankine superheat cycle, the Rankine reheat cycle and the regenerative cycle.

Central to expertise the operation of steam propulsion is the primary steam cycle, a method wherein we generate steam in a boiler, increase the steam via a turbine to extract work, condense the steam into water, and sooner or later feed the water again to the boiler.
Reheat now no longer best correctly decreased the penalty of the latent warmness of vaporization in steam discharged from the low-stress quit of the turbine cycle, however, it additionally advanced the first-rate of the steam on the low-stress quit of the mills via way of means of decreasing condensation and the formation of water droplets inside the turbine.

Read more about the Boiler:

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7 0

2 years ago

Based on the following passage on construction technology during the Middle Ages, why might a worker not be allowed

KonstantinChe [14]

Answer:

A guild are an association of skilled merchants, craftsmen and artisans that provide support and protection for their members and push their professional interest forward and further their craft

Because the guild guild members mainly gained their skill through knowledge passed to them by their family bloodlines, other unskilled workers were by not being schooled on the craft and by family tradition not allowed to join a guild based on the nature knowledge transfer the guild members have which is mainly several generations of family trade trainings

Explanation:

4 0

3 years ago

Read 2 more answers

Ldentiy three industries that often need the skills of mechanical engineers. Briefly explain the skills that mechanical engineer

const2013 [10]

Answer:

3 industries that often need the skills of mechanical engineers are:

Automotive industry

Construction industry

Aerospace industry

The key skills mechanical engineers bring to these industries are effective technical skills, the ability to work under pressure, problem-solving skills, creativity and teamwork.

Explanation:

Automotive industry: The skills mechanical engineers bring to automotive industry include designing new cars for development, conducting laboratory testing for performance safety, and troubleshooting design or manufacturing issues with recalled vehicles. Automotive engineers have:

good mathematical skills, for instance in calculating the stresses power trains and other parts have to withstand;

understanding and application of principles of physics and chemistry to properly design engines, electrical systems and other car components;

good computer skills, because 21st century engineers rely on computer-assisted design software;

knowledge of ergonomics, which is applied in the process of designing a car so that the driver and passengers have a comfortable and functional environment, is another skill mechanical; engineers need.

Construction industry: Mechanical engineers are responsible for designing, building, establishing, and maintaining all kinds of mechanical machinery, tools, and components in the construction industry.

Aerospace industry: Mechanical engineers in aerospace industry produce specifications for design, development, manufacture and installing of new or modified mechanical components or systems. They design more fuel-efficient aircraft that cut emissions and build the fleets of satellites that power modern GPS technology.

4 0

3 years ago