Consider a 1.5m long 30cm wide flat plate exposed to two laminar flows of air (6 m/s free stream top surface and 12m/s free stream bottom surface) at 25ºC and atmospheric pressure. The top and bottom surfaces of the plate are electrically heated (1.5 kW total power, heaters assumed infinitesimally thin). The plate consists of 3 layers: a top and bottom layer of 1.0 cm balsa wood (k = 0.055 W/(m·K)), and a middle layer of 2.0 cm plywood (k = 0.12 W/(m·K)). Assume all of the following conditions apply: a) the generated surface heat flux on the top and the bottom surfaces of the plate is uniform; b) the heat is transferred by convection on both sides of the plate; c) radiation heat transfer is negligible; and d) heat transfer is one-dimensional through the plate and no heat is transferred along the plate. Assume transition occurs at Rex=30,000 for this plate.
•Calculate and plot the expected top, bottom and center temperatures in °C as a function of distance from the leading edge of the plate.
In: Mechanical Engineering
Research and write a recommendation report that compares two or more things. Address a topic or issue of your major field of study.
In: Mechanical Engineering
An FCC crystal is pulled in tension along the [100] direction. (a) Determine the Schmid factor for all slip systems. (b) Identify the slip system(s) that would be activated first. (c) What is the tensile stress under which this crystal will flow plastically? (τo = 50 MPa)
In: Mechanical Engineering
In a slowly cooled hypereutectoid iron-carbon steel,
the pearlite colonies are normally separated from each
other by a more or less continuous boundary layer of
cementite. Explain how this microstructure develops. Use
simple sketches to illustrate your answer
In: Mechanical Engineering
In slowly cooled hypoeutectoid steels one normally finds a microstructure in which the pearlite colonies are surrounded by ferrite grains. Explain.
In: Mechanical Engineering
Problem 7.56
A three-point bending test was performed on an aluminum oxide specimen having a circular cross section of radius 4.7 mm; the specimen fractured at a load of 3740 N when the distance between support points was 44 mm. Another test is to be performed on a specimen of this same material, but one that has a square cross section of 11 mm in length on each edge. At what load would you expect this specimen to fracture if the support point separation is maintained at 44 mm?
In: Mechanical Engineering
Article on leadership and related to mechanical engineering.
In: Mechanical Engineering
The rate of emission of SO2 from the stack of a power plant is 150 gm/sec. The stack height is 50 m. Calculate the effective plume height on a sunny September day when the wind velocity is 5 m/sec. Use Class B stability. The effluents are being released at 10m/s and at a temperature of 310oK. The atmospheric temperature is 293oK. The stack diameter is 0.5 m
In: Mechanical Engineering
I need to Elaborate a thermodynamic analysis of energy and efficiency of traditional and Perovskite solar cells. Can I get Help with this?
In: Mechanical Engineering
Calculate the maximum mass flow possible through a frictionless, heat-insulated, convergent nozzle if the entry or stagnation conditions are 5 bar and 15°C and the throat area is 6.5 cm2. Also calculate the temperature of the air at the throat. Take cp = 1.00 kJ kg−1 K−1 and γ = 1.4.
In: Mechanical Engineering
Air at 5 bar and 560K is expanded in steady flow in a horizontal
convergent–divergent duct to an exit velocity
of 640 ms−1. The walls of the duct are heated so as to keep the
temperature drop to one-half the value of an
isentropic expansion to the same velocity and pressure from the
same initial conditions. Calculate, assuming
negligible initial velocity:
a. the heat supplied;
b. the final temperature;
c. the mass flow rate per square metre of exit area.
In: Mechanical Engineering
Which type of motor is hydraulically balanced so as
not to have buckling forces on the drive shaft.
(A) Gear
(B) Palettes
(C) Pistons
And Why?
The pressure compensator in which type of hydraulic
piston motor is used.
(A) Axial
(B) Inclined axis
(C) Alternative
And Why?
The pressure plate is used in the manufacture of the
motor of:
(A) Gear
(B) Palettes
(C) Pistons
And Why?
Thank you for your time, have a nice day :)
In: Mechanical Engineering
Which type of motor is hydraulically balanced so as
not to have buckling forces on the drive shaft.
(A) Gear
(B) Palettes
(C) Pistons
And Why?
The pressure compensator in which type of hydraulic
piston motor is used.
(A) Axial
(B) Inclined axis
(C) Alternative
And Why?
The pressure plate is used in the manufacture of the
motor of:
(A) Gear
(B) Palettes
(C) Pistons
And Why?
Thank you for your time, have a nice day :)
In: Mechanical Engineering
The composite walls of a building are made up of three materials. The inside layer of the walls is 1-cm thick wall board (kwb = 0.2 W/mK). The middle layer is 10 cm thick insulation (kI = 0.06 W/mK) and the outside layer is 3 cm of wood (kw = 0.15 W/mK). The total wall area is 350 m2. The outside air temperature is -10 oC and the inside air temperature is maintained at 20 oC. The inside and outside average convective heat transfer coefficients are 7 and 35 W/m2K, respectively. You are asked to: a. Sketch and label the thermal circuit diagram for the rate of heat transfer, q, from the inside of the room, through the composite walls and to the outside. Evaluate all individual thermal resistances, the total thermal resistance and the overall heat transfer coefficient. [10] b. Evaluate q. [2] c. Determine the unknown temperatures on both sides of the insulation layer. [3] Hint: Neglect radiation, contact resistance and conduction in air. The walls are large enough so that 1-dimensional conditions exist.
In: Mechanical Engineering
There are proposals to store energy in flywheels for load
leveling in utility systems.
During the off-peak period for energy demand at night, these
flywheels are charged
to high speeds. At peak periods during the day, this energy is
supplied back to the
utility.
How would ASDs play a role in this scheme? And what is the role of
electric drives in electric transportation systems of various
types?
In: Mechanical Engineering