Questions
‏The ceiling of an ice skating rink should have a high reflectivity to avoid condensation on...



‏The ceiling of an ice skating rink should have a high reflectivity to avoid condensation on the ceiling . If condensation forms on the ceiling , water may drip ca ice . The rink has a diameter of 50m and a height of 12m . The temperature of the ice and walls are -5 ° C and 15 ° C respectively . The air in the rink is also at 15 ° C Neglect the convective losses to the outside air . If the ceiling is a diffese - gray surface and the ice and walls can be approximated as black bodies , perform an energy balance on the ceiling to calculate the ceiling temperature . If the relative humidity of the rink air is 70 % and the dew point is 9c , will condensation occur if a coating is added that provides an emissivity of 0.05 ?

In: Mechanical Engineering

Air enters the turbine of a gas turbine at 1400 kPa, 1400 K, and expands to...

Air enters the turbine of a gas turbine at 1400 kPa, 1400 K, and expands to 100 kPa in two stages. Between the stages, the air is reheated at a constant pressure of 350 kPa to 1400 K. The expansion through each turbine stage is isentropic.

Determine:

(b) the heat transfer for the reheat process, in kJ/kg of air flowing.

(c) the increase in net work as compared to a single stage of expansion with no reheat.

In: Mechanical Engineering

hi please elaborate axial flow pumps working principle with labelled and the flow image , application...

hi please elaborate axial flow pumps working principle with labelled and the flow image , application and limitation .

In: Mechanical Engineering

Hello! In Ansys Fluent, how can I calculate the molar concentration (kmol/m^3) of a species and...

Hello! In Ansys Fluent, how can I calculate the molar concentration (kmol/m^3) of a species and molar fraction (dimensionless) of a species in fluent after I put an exact amount of the mass (kg) of a species at a boundary? Thank you, I will thumb you up!

In: Mechanical Engineering

Make a mindmap that contain: a- Relationship between Mechanical Energy Equation and internal flow analysis. b-...

Make a mindmap that contain:

a- Relationship between Mechanical Energy Equation and internal flow analysis.

b- Flow regimes - Search on the turbulent, laminar and transitional flow regimes. Describes them and give example when/where they occurs.

c- Region in pipe flow - Search on hydrodynamic entrance length, boundary layer region/viscous flow region, hydrodynamically developing region and hydrodynamically fully developed region. Describes them and show how to calculate them.

In: Mechanical Engineering

Give two practical examples for following concepts/principles. Also write where these are used with brief explanation:...

Give two practical examples for following concepts/principles. Also write where these are used with brief explanation: (a) Centroid (b) Moment of inertia (c) General plane motion (d) Work energy principle (e) Impulse-momentum principle

In: Mechanical Engineering

Force (N) time (s) Elongation (t*0.05 mm/s) Engineering stress(Mpa) Engineering Strain 0 0 0 0 0...

Force (N)

time (s)

Elongation (t*0.05 mm/s)

Engineering stress(Mpa)

Engineering Strain

0

0

0

0

0

1500

5

0.25

53.05978069

0.00625

5000

10

0.5

176.8659356

0.0125

9250

20

1

327.2019809

0.025

11250

25

1.25

397.9483551

0.03125

11750

30

1.5

415.6349487

0.0375

11500

32.5

1.625

406.7916519

0.040625

12000

35

1.75

424.4782455

0.04375

14250

50

2.5

504.0679165

0.0625

15250

60

3

539.4411036

0.075

16000

70

3.5

565.970994

0.0875

16750

85

4.25

592.5008843

0.10625

17250

100

5

610.1874779

0.125

17500

132.5

6.625

619.0307747

0.165625

17250

170

8.5

610.1874779

0.2125

17000

180

9

601.3441811

0.225

16500

190

9.5

583.6575875

0.2375

16250

195

9.75

574.8142908

0.24375

16000

200

10

565.970994

0.25

15000

210

10.5

530.5978069

0.2625

13250

220

11

468.6947294

0.275

12697.1

222.5

11.125

449.1368942

0.278125

Initial Length (mm)

Initial Diameter(mm)

Area = pi*r^2

40

6

28.27

Maximum load capacity: 50,000 N Test rate: 3 mm/min - 0.05 mm/s Steel A Steel B Initial length, Lo 40 mm 40 mm Initial diameter, do 6 mm 6 mm Final length, Lf 48 mm 52 mm Final diameter, df 4.2 mm 3.1 mm  

From the data given in excel file, calculate:

(b) Tensile strength, modulus of elasticity, modulus of resilience, % elongation and % reduction in area.

(c) Plot both engineering stress strain curve and true stress strain curve.

(d) Compare the tensile behaviour of steel A and B in one paragraph

In: Mechanical Engineering

For an ideal gas-turbine cycle with two stages of compression and two stages of expansion, the...

For an ideal gas-turbine cycle with two stages of compression and two stages of expansion, the pressure ratio across each stage of the compressor and turbine is 3. The air enters each stage of the compressor at 300 K and each stage of the turbine at 1200K. Using variable specific heats, determine the back work ratio and the thermal efficiency of the cycle, assuming

(a)no regenerator is used,

(b)a regenerator with 75% effectiveness is used.

In: Mechanical Engineering

Write a detailed understanding about the history, current trends and future research of 'Ground Support Vehicles...

Write a detailed understanding about the history, current trends and future research of 'Ground Support Vehicles for Guided Missile Programme' pertaining to India and also the international scenario. Include case studies.

In: Mechanical Engineering

As a person serving in the role of a safety practitioner, how would you explain to...

As a person serving in the role of a safety practitioner, how would you explain to a new worker the difference between engineering and administrative controls and how they relate to a specific work environment? Be specific in your response, and include examples of your work environment.

l
t)

In: Mechanical Engineering

A single-cylinder, four stroke research engine operates on Otto cycle. The specification of the engine is...

A single-cylinder, four stroke research engine operates on Otto cycle. The specification
of the engine is shown as below:-
Displacement volume of the cylinder = 540 cm3
Clearance volume of the cylinder = 60 cm3
Minimum temperature = 200°C
Minimum pressure = 200 kPa
Net work output = 1000 kJ/kg
Sketch the process on a P-V diagram and by using constant specific heat at room
temperature, determine:
i) the temperature and pressure at each process,
ii) the thermal efficiency of the engine, and
iii) the Mean Effective Pressure (MEP).

In: Mechanical Engineering

An Otto Cycle engine operation at cold-air standard has a volume of 0.1908 at the beginning...

An Otto Cycle engine operation at cold-air standard has a volume of 0.1908 at the beginning of isentropic compression. If the compression ratio is 12.5, how much heat is released from the fuel per kg of fuel burned if the fuel consumption is 0.02 kg/min? The mean effective pressure is 350kPa.

In: Mechanical Engineering

heat transfer question, show equations, assumptions, calculations and steps clearly. will give thumbs up rating if...

heat transfer question, show equations, assumptions, calculations and steps clearly. will give thumbs up rating if solved correctly in 30 minutes

Define thermal diffusivity (α) and give its mathematical expression.

In: Mechanical Engineering

A double pane window consists of two pieces of glass each of 8 mm thick that...

A double pane window consists of two pieces of glass each of 8 mm thick that enclose an air space of 8 mm thick. The window separates room air at 18°C from outside ambient air at -8°C. The convection coefficient associated with the inner (room-side) surface is 12W/m2 .K. The thermal conductivity of the glass is kg=1.35 W/m. K and that of the air is ka=0.027 W/m. K Q1- If the outside air convection coefficient is ho = 76 W/m2 .K what is the heat loss through a window that is 0.8 m long by 0.5 m wide? Neglecting radiation and assume the air enclosed between the panes to be stagnant. Q2- We consider now that the heat transfer in the air gap is transferred by conduction and radiation and that the radiation coefficient hrad = 3 W/m2 K . Show the thermal circuit representing the steady state situation and define the new heat transfer loss through the window.
(Non-anonymous question )
Your name and file upload actions will be recorded in OneDrive and visible to the form owner.

In: Mechanical Engineering

Please describe in detail your knowledge of electrical engineering? Please describe in detail your knowledge of...

Please describe in detail your knowledge of electrical engineering?

Please describe in detail your knowledge of mechanical engineering?

Please describe in detail your knowledge of computer software?

What does customer service mean to you?

What interests you most about this position?

What are your career goals?

Why are you looking for another job?

What is your business travel tolerance?

What has been your business travel levels in your past opportunities?

In: Mechanical Engineering