Why do we use angled drafts in casting
In: Mechanical Engineering
A 0.2 m^3 piston/cylinder contains air at 400 K and 400 kPa and receives heat from a constant temperature heat source at 1300 K. The piston expands at constant pressure to a volume of 0.6 m^3. Determine the change of availability of the system. Assume To= 300K and Po = 100kPa.
Answer should be 210.3 kJ.
In: Mechanical Engineering
How does shot peening introduce residual stresses over a material surface?
Explain its mechanism by drawing the material surface plastically deformed as a result of the impact of the shot.
In: Mechanical Engineering
Consider the combined power cycle for which Qin=Qin1 ,Qout=Qout2 and Wcycle=Wcycle1 + Wcycle2. Derive an expression for the thermal efficiency ? of the combined power cycle in terms of ?1 and ?2.
Prove that ? > ?1 and ? > ?2. In plain English, you are being asked to prove that the combined power cycle is more efficient than each of the two cycles alone [Hint: Starting from the expression for ? derived in part (ii), each of the two proofs requires exactly one additional step and no more.]
In: Mechanical Engineering
Explain the significance of statistical scatter in fatigue life, especially how this may affect the use of S-N curves for engineering purposes.
In: Mechanical Engineering
Describe the general and specific industry application in relation to the Bonfiglioli VF 30 gearbox design.
In: Mechanical Engineering
A Rankine cycle uses water as its working fluid. The mass flow rate of water through the cycle is 150 kg/s. Superheated vapour exits the boiler at 8 MPa and 560 °C. The condenser pressure is 8 kPa. The water at the pump inlet is 35 °C. The isentropic efficiency of the pump is 75% and the isentropic efficiency of the turbine is 91%. The turbine and pump can be treated as adiabatic. The pressure drops of the working fluid as it follows through the boiler and through the condenser are negligible. Kinetic and potential energy effects can also be ignored. For your analysis use the state point numbering scheme indicated in the following schematic: Do the following:
I. Draw the state points on a T-s diagram. Take care to locate each point in the correct region: superheated, mixed and subcooled.
II. Calculate the power developed in by the turbine.
III. Calculate the rate of heat transfer to the steam passing through the boiler.
IV. Calculate the power consumed by the pump in MW.
V. Calculate the rate of heat transfer from the cycle to the cooling water in the condenser in MW.
VI. Calculate the cycle’s back work ratio.
BONUS: Comment on state 2, what kind of effect can this have on the turbine performance?
In: Mechanical Engineering
two subway cars as shown in Figure 1 have mass m = 2000 kg and are connected by a coupler that can be modeled as a spring of stiffness k = 280,000 N/m. Use Newton’s method to derive the equations of motion, calculate the natural frequencies and determine the associated mode shapes. also, find the time response x1(t) and x2(t) of the subway initial conditions: x(0)= [ 0, 0.2] with zero initial velocity vector.
In: Mechanical Engineering
Impact of contemporary robotics in Germany
In: Mechanical Engineering
My goal is to be a NC-programmer of CNC machinist.
"Describe/illustrate if all conditions were ideal and you believed that all things were possible, what would you seek to achieve as your life's work or major accomplishment?"
Please write the answer at least 200 words. Thanks.
In: Mechanical Engineering
Studs used in a turbo pump were made from 0.35C-1.5Ni-1.0Cr-0.2Mo steel, quenched and tempered to 400 HV hardness, cadmium-plated and baked at 200°C for 2 h. The studs used in a turbo pump failed after 3 months of assembly. A fractograph of a failed stud revealed a predominantly intergranular mode mixed with ductile failure features. Increasing the baking time to 12 h considering the low diffusivity of hydrogen across the relatively impervious cadmium coating solved the problem. Explain the cause and mode of this failure.
In: Mechanical Engineering
Problem 1.Historical data is collected
from an assembly process that consists of 5 operations. Determine
the Rolled-Throughput Yield, Normalized Yield, Normalized Defects
per Unit, and Total Defects per Unit (TDPU), given the following
historical production data:
|
Operation |
Opportunities per Unit |
Units Produced |
Defects Recorded |
|
Build Rotating Group and Inspect |
10 |
851 |
75 |
|
Install Rotating Group in Housing and Install Fittings |
7 |
1202 |
72 |
|
Perform Functional Test |
5 |
943 |
82 |
|
Clean and Paint with Final Inspection |
3 |
894 |
70 |
|
Install Pulley and Labels |
4 |
1200 |
88 |
In: Mechanical Engineering
List the processes in each Rapid-prototyping class??
1- Subtractive.
2- Additive.
3- Virtual.
In: Mechanical Engineering
What is the therotiacal And The expertmatla heat transfer cofficnent for heat exchanger in my case shell and tube
Therotical ?
formual ??
expermantial ?
formula ?
I am uisng LMTD method
In: Mechanical Engineering
A model aircraft in a wind tunnel with a wing area of 0.9 square meters and a chord of .24 meters is subject to a sea level standard airflow at 130 m/sec. The zero-lift moment about the center-of-gravity is measured as – 7.8 N m. At a different angle of attack, the moment about the center-of-gravity is measured as 13.5 N m with a lift of 2,650 N.
(A)Calculate the value of the moment coefficient about the aerodynamic center, and the location of the aerodynamic center (relative to the cg).
(B) Lead is added to the tail so that the center-of-gravity is shifted aft by 25% of the chord. Calculate the moment about the center-of-gravity with a lift of 3,000N.
In: Mechanical Engineering