Considering the nature of the Charpy impact test can the impact energy values obtained from it be used directly in mechanical design? Explain your answer. ?
In: Mechanical Engineering
[Aerospace Engineering]
1. Aerodynamics :
(a) how to find zero lift line of a wing and airfoil?
(b) how do we relate this with climb angle(gamma), pitch angle(theta), angle of incidence, and Angle of Attack(Alpha)
(c) why during climb Theta is not considered as Angle of attack since the aircraft moves with respect to x-axis? or is that with respect to thrust direction?
(d) then can we classify Angle of Attack to be similar with Angle of Incidence if the aircraft flies along the direction of thrust?
2. Flight Mechanics :
a) what is the differences between stick-fixed and stick-free? (including explanation on each)
b) consider that the aircraft flies in autopilot mode, is that considered as stick-fixed,free, or neither?
c) Consider Horizontal stabiliser on conventional aircraft, how to find these variables? given
C_LT = 2*phi*Alpha_Teffective + a2(eta) +a3(beta), ; C_LT is known, Aileron hinge location x1/c = 0.65 and Trim Tab hinge at x2/c = 0.8
C_H = b1*Alpha_Teffective + b2(eta) + a2(beta), ;beta = Trim tab deflection angle; eta = Elevator deflection angle
In: Mechanical Engineering
A boiler produces steam at a saturated temperature of 300C and at dryness of 92% from feedwater at 110C The boiler evaporating rate is 70 kg min. What is boiler heat rate ?
The density of steam at pressure 1.100 kPa is ?
In: Mechanical Engineering
For a brass alloy, the tensile strength is 400 MPa, the yield strength is 315 MPa and the modulus of elasticity is 100 GPa.
(a) What is the maximum load that may applied to the specimen with a cross sectional area of 130 mm2 before it fractures?
(b) For the same cross sectional area, if the original length of the specimen is 75 mm what will be the length of the specimen, when a load of 13000 N is applied in the longitudinal direction?
In: Mechanical Engineering
Consider a pipe (diameter of 50 mm) with air flowing through it.
The inlet conditions are: Mach 3; total pressure = 1000 kPa and 550
K. The friction coefficient (f) is 0.004. The exit Mach number
decreases with the length of the pipe. Assume adiabatic, steady
flow.
Write a short Matlab code and plot the following,
while the exit Mach number changes from 2.5 to 0.99 with increments
of ?M=0.01. Find the length of the pipe that is going to give the
desired exit Mach number. Find the pipe exit pressure, pipe exit
temperature, and pipe exit total pressure.
In: Mechanical Engineering
what happens to cutting force as the following increase: a.Rake angle b.Material shear strength c.Depth of cut Are your findings as expected based on the theory of machining? Why or why not?
In: Mechanical Engineering
Name three professions related to kinesiology and explain how each will benefit from a knowledge of biomechanics.
In: Mechanical Engineering
How much energy does it require to keep the ice steady at -8 degrees celsius continuously?
We have an ice rink and these are the values:
- indoor climate has a constant temperature of +10 degree celsius
- It took 17669880 KJ to cool it down from +10 celcius to -8 celcius.
- Dimensions 60m length x 30m width x 2.5cm thickness, which is 45 cubic meter of ice
How much energy is needed to keep the rink cooled down at -8 degrees per hour?
In: Mechanical Engineering
Which of the following is least likely to decrease the thermal contact resistance between two media in contact?
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Make a vacuum gap at the interface |
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Apply thermal grease onto the interface |
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Sand the contact surface smooth |
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Apply pressure one against another |
In: Mechanical Engineering
What are uniform pressure and uniform wear theories? Deduce expressions for the friction torque considering both the theories for a flat collar.
In: Mechanical Engineering
In: Mechanical Engineering
Create and complete a function M-file that will receive an input, ? , and output the corresponding conversion to radians within the range of a complete circle. For each 30? increment, the output should be displayed as a string, (i.e. pi/2 , pi/4 ,etc.), and any other degree to be displayed numerically.
I'm using Matlab, explanations are appreciated.
In: Mechanical Engineering
A greenhouse (30’x20’x10’) in Yuma, Arizona needs to be cooled from an outside temperature of 110oF to an indoor 75oF. The RH outside is 4% and the greenhouse requires 5 air changes per hour. Determine the amount of water required per hour to achieve this level of Evaporative cooling. Please state your answer in pounds of water.
State ALL assumptions, Show all work for full Credit
In: Mechanical Engineering
Which one of the following statements are correct?
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In a counter-flow heat exchanger, the exit temperature of the cold fluid can never reach the exit temperature of the hot fluid. |
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In a parallel flow heat exchanger the exit temperature of the cold fluid is always greater than the exit temperature of the hot fluid. |
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In a counter flow heat exchanger the exit temperature of the cold fluid is always greater than the exit temperature of the hot fluid. |
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In a parallel flow heat exchanger the exit temperature of the cold fluid can never reach the exit temperature of the hot fluid. |
In: Mechanical Engineering
How does interphase precipitation work for alloy hardening?
Name two characterisation techniques that could be used to image interphase precipitation.
In: Mechanical Engineering