Compare the three types of lubrication systems for plain bearings using sketches and Bearing Parameter/ Stribeck Curve.
In: Mechanical Engineering
What are Fixed side and Floating side bearing arrangement? Explain their applications with sketches.
In: Mechanical Engineering
An airfoil profile to be used on a wind turbine blade is tested in a wind tunnel. The prototype (full-scale) airfoil section has a chord length of 2m and moves at 50 m/s relative to the wind, the wind tunnel model has a chord length of 0.4m. The temperature for the model test is the same as for prototype operation.
(a) What criterion should be used to obtain dynamic similarity in the experiment? (Write out the criterion in an equation.) (b) What velocity should the wind tunnel be operated at to have dynamic similarity for the scale model? (assuming tests at atmospheric pressure.) (c) The wind tunnel available for this test can only be operated at 100 m/s, but it can also be pressurized. What pressure should be used in the wind tunnel to have dynamic similarity? (Assume the air behaves like an ideal gas.)
In: Mechanical Engineering
Along, square, electrical heating element standing on a corner with one side of the square heating element being 25mm, thermal conductivity k = 240 W/m ? K, density ñ = 2700 kg/m3, and specific heat cp = 900 J/kg ? K is installed in a duct for which air moves in cross flow over the heater at a temperature and velocity of 30°C and 10 m/s, respectively.
(a) Neglecting radiation, estimate the steady-state surface temperature when, per unit length of the heater, electrical energy is being dissipated at a rate of 1000 W/m. ?
(b) If the heater is activated from an initial temperature of 30°C, estimate the time required for the surface temperature to come within 20°C of its steady-state value. ?
In: Mechanical Engineering
what are the differences of all these cooling load calculation methods? What are the full name of these methods and the strength and limitation of these approaches?
a)HB method
b)CLTD method
c)RTS method
In: Mechanical Engineering
In: Mechanical Engineering
Answer the following questions:
1. What is PFCU functions and State the advantage and Disadvantages of PFCU?
2. What do you understand about fly by wire?
Answer the questions in paragraph form.
Copied answer will get 60%
In: Mechanical Engineering
A manufacturer wishes to choose between two ceramics for a certain application. Data for the two ceramics tested under identical conditions were as follows:
| Ceramic | Mean Fracture Stress | Weibull Modulus |
| A | 500 MPa | 12 |
| B | 600 MPa | 8 |
The service conditions are geometrically identical to the test conditions and impose a stress of 300 MPa. By constructing Weibull graphs with S = 1/2 for mean fracture stress or any other method, decide which ceramic will be more reliable and compare the probabilities of failure at 300 MPa. At what stress would the two ceramics give equal performance?
Answer: Stress for equal performance = 349 MPa
In: Mechanical Engineering
Use the Navier-Stokes equations to show how pressure varies with x, y and z in a hydrostatic fluid.
In: Mechanical Engineering
A velocity field is described by the following equations: ?? = 10y/(x^2 +y^2) , ?? = -10x/(x^2+y^2) , and w=0 (a) Is this flow compressible or incompressible? (b) Find the pressure gradient. Assume frictionless flow in the z-axis, the density is 1.2 kg/m3 , and the z-axis is aligned with gravity. Also assume the normal and shear effects are negligible.
In: Mechanical Engineering
For the case of incompressible flow, write all 3 components of the Navier-Stokes equations and the complete form of the differential continuity equation.
In: Mechanical Engineering
8.8. Consider blood flow in a vessel (i.e., a pipe with a porous wall that is permeable to blood). The radius and length of the vessel are R and L, respectively. In general, the flow is axisymmetric, the fluid velocity has both radial and axial components that are usually determined numerically. However, there are two approximate solutions to this problem. One is to use lubrication theory to determine the relationship between the flow rate and the pressure gradient in the vessel is R<<L. The other is to estimate the axial velocity component by solving a standard problem of unidirectional flow in a pipe with an impermeable wall, but with a different kind of no-slip condition at the wall. The conventional no-slip condition is replaced by the equation: k1/2 (du/dr)= -a*u
where k is the specific hydraulic permeability of the wall, u is the axial velocity of the fluid, r is the radial coordinate, and a is a dimensionless quantity that depends on the microstructure of the porous wall. The value of a usually varies between 0.1 and 10 depending on the size of the pores in the pipe wall.
(a) Determine the axial velocity profile in the vessel using the second approach.
(b) Find the flow rate through the vessel
(c) Estimate the slip effect a on the pressure drop of the flow rate through the pipe
In: Mechanical Engineering
Water at 300kPa and 20oC is heated in a chamber by mixing it with superheated steam at 300kPa and 300oC. The cold water enters the chamber at a rate of 1.9 kg/s. Calculate the mass flow rate of the superheated steam, if the mixture leaves the chamber at 60oC.
answer is ______kg/s
If necessary, define system and energy flows shown on sketch. Complete solution shown analytically before numbers.
In: Mechanical Engineering
In: Mechanical Engineering
How are the requirements for a design project developed?
In: Mechanical Engineering