Argon gas enters an adiabatic compressor at 16.0 psia with 99 F with a velocity of 49.9 ft/s. It exits at 225 psia and 209.5 ft/s. If the isentropic efficiency of the compressor is 83.1%, determine:
a) the exit temperature (R) of the argon
b) the work input to the compressor (Btu/lbm)
In: Mechanical Engineering
A Rankine cycle with reheat produces 1 MW of net power. The boiler operates at 15 MPa and has an outlet temperature of 800 K. The condenser operates at atmospheric pressure (1 atm). The operating point of this cycle is such that the water exiting the low pressure turbine has no liquid present to prevent damageto the turbine (hint: what does this say about quality at this point?). Assume the pump and second turbine stage are both isentropic, but the first turbine stage has an isentropic efficiency of 90%. Assume the steam is reheated at a pressure of 1 MPa.
Find:
(A)The mass flow rate of steam through the turbines
(B)The required heat input
(C)The required flow rate of fuel given a heating value of 50 MJ/kg
(D)Plot the state points on a T-s diagram with lines of constant pressure at the boiler,reheat, and condenser pressures.
In: Mechanical Engineering
Explain how Doppler (Fuel Temperature Coefficient) changes as fuel temperature rises. Why does this occur? A picture will be helpful.
In: Mechanical Engineering
Show to use ode45 built-in function in MATLAB to solve the following ODE problem:
dydx=x^2 / y y(0)=2
Calculate y(x) for 0 ? x ? 20 and compare the results to analytical solution y = sqrt((2x^3 / 3) + 4)
In: Mechanical Engineering
1. What has the greatest influence on the length and detail of a process plan, and why?
2. What usually determines the way a process plan starts out?
In: Mechanical Engineering
In: Mechanical Engineering
1)Describe what a “riser” is in the context of sand casting.
What are its functions?
In light of Chvorinov’s rule, what should be taken into account
when determining the geometry, dimension, and
location of a riser in a sand casting
mold?
In: Mechanical Engineering
1)Describe what a “riser” is in the context of sand casting.
What are its functions?
In light of Chvorinov’s rule, what should be taken into account
when determining the geometry, dimension, and
location of a riser in a sand casting
mold?
In: Mechanical Engineering
The spectral absorptivity of a large diffuse surface is
????=0.850 for ??<1???? and ????=0.25 for ???1????. The bottom
of the surface is well insulated, while the top may be exposed to
one of two different conditions.
(a) In case (a) the surface is exposed to the sun, which provides
an irradiation of ????=1200 W/m2, and to an airflow for which T =
300 K. If the surface temperature is Ts =320 K, what is the
convection coefficient associated with the airflow?
(b) In case (b) the surface is shielded from the sun by a large
plate and an airflow is maintained between the plate and the
surface. The plate is diffuse and gray with an emissivity of
????=0.8. If ???=300 K and the convection coefficient 30 W/m2K,
what is the plate temperature Tp that is needed to maintain the
surface at Ts =320 K?
(c) in case (b) the large surface and the plate both have a
dimension of 8m by 8m, and the separation distance is 2m. The other
conditions remain the same. What would be the plate temperature
that is needed to maintain the surface at Ts=320K?
In: Mechanical Engineering
Two parallel rectangles having emissivities of 0.6 and 0.9 are
each 1.2 meters wide and 2.4
meters high. They are positioned 0.6 meters apart. The plate with ?
= 0.6 is at 1000 K while the other is
420 K. The surroundings are at 290 K and may be assumed to absorb
all energy that escapes the two plates.
(a) What is the total energy lost (Watts) from the hotter plate
(radiosity)?
(b) What is the radiant energy exchange (Watts) between the two
plates?
In: Mechanical Engineering
In the rolling lab we measured the following conditions:
R = 32.25; % roller radius (mm)
Nr = 30; % roll rotational speed in rpm
A 8-pass flat rolling process was performed with one set of workpiece dimensional data of length l, width w, and thickness t, measured as below:
(with the first set of data for initial solder wire, and the rests are the outlet dimensions of each pass)
l = [37.85 39.55 41.39 45.96 50.19 59.83 79.64 127.5 260.0]; %length (mm)
w = [2.92 3.22 3.51 3.63 3.76 4.02 4.21 4.30 4.35]; %width (mm)
h = [2.92 2.38 2.059 1.672 1.470 1.126 0.802 0.468 0.177]; %thickness (mm)
The total rolling time for each pass is:
t = [0.35 0.39 0.44 0.48 0.58 0.78 1.25 2.55];
Express the x-component of the velocities of the roll vr(x) and the workpiece metal vm(x) as a function of x (where x is in rolling direction and x=0 at the outlet section), for each pass, and plot vr(x) and vm(x) for each pass in one figure
In: Mechanical Engineering
A Cessna 172 has the following characteristics: Wingspan: 36’ 1” Wing Area: 174 ft2 Normal Gross Weight: 2,450 lb Fuel Capacity: 54 gal of aviation gasoline Power Plant: 1 × Lycoming IO–360–L2A piston engine, 180 hp Specific Fuel Consumption: 0.3 lb/hp-h Parasite drag coefficient: CD,0 = 0.037 Oswald efficiency factor: e = 0.72 Propeller efficiency: 0.8 #Passengers: 3 (+1 pilot)
(a) Produce a plot showing the power required vs. velocity of the aircraft. Label the axes clearly. [Use Excel or a programming language of your choice]
(b) Produce a plot showing the L/D ratio vs. velocity. Label the axes clearly. [Use Excel or a programming language of your choice]
(c) What is the maximum velocity at sea level?
(d) What is the minimum flight velocity at sea level?
(e) What is the maximum velocity at 5,000 ft?
(f) What is the maximum rate of climb?
(g) What is the service ceiling?
(h) How long does it take to get to the service ceiling?
(i) If you run out of fuel at an altitude of 5,000 ft, how far can the plane glide?
(j) What is the maximum range?
(k) What is the range at maximum velocity?
(l) What is the maximum endurance?
(m) What distance is required for takeoff?
(n) What distance is required for landing?
In: Mechanical Engineering
An automotive engine develops maximum torque at a speed of 1000 rpm At this speed, the power developed by the engine is 25 kW. The engine is equipped with a single plate clutch having two pairs of friction surfaces. The mean diameter of the friction disk is 190 mm and the coefficient of friction is 0.35. Six springs, with a spring index of 6, provide the necessary axial force. The springs are made of patented and cold-drawn steel wires of Grade 2 (G = 81 370 N/mm2). The permissible shear stress can be taken as 50% of the ultimate tensile strength. Determine the wire diameter of the spring.
In: Mechanical Engineering
A component requires two (2) operations to complete it. The first operation has the following information: Machining Time = 2.445 min., Handling Time = 1.334 min., Tool Change Time = 21.45 min. which needs to be changed every 1675 pieces with a Tool Cost of $133.00 per tool. The operational cost for the first operation = $116.67 per hour. The second operation has the following information: Machining Time = 1.436 min., Handling Time = 0.849 min., Tool change Time = 18.75 min. which needs to be changed every 970 pieces with a Tool Cost of $68.40 per tool. The operational cost for the second operation = $116.67 per hour. What is the total Cost for the component?
In: Mechanical Engineering
Write and test MatLAB code implementing the mathematical models of the boundary value problem to evaluate the elastic deflection of the beam based on Euler-Bernoulli and Timoshenko theories with finite difference discretisation (for numerical integration and differentiation). The results must be plotted on a graph with labelled local maxima and minima
In: Mechanical Engineering