6) A tapered surface is to be turned on an automatic lathe. The work piece is 900 mm long with minimum and maximum diameters of 150 mm and 300 mm at opposite ends. The automatic controls on the lathe permit the surface speed to be maintained at a constant value of 200 m/min by adjusting the rotational speed as a function of work piece diameter. Feed=0.25 mm/rev and depth of cut = 3.5 mm. The rough geometry of the piece has already been formed, and this operation will be the final cut. Determine (a) the time required to turn the taper and (b) the rotational speeds at the beginning and end of the cut. (c) Suppose that the automatic lathe surface speed is not available and a conventional lathe must be used. Determine the rotational speed that would be required to complete the job in exactly the same time as in part (a) of the problem.

how does hot and cold working affect work hardening?

Provide a sketch of how the tensile strength and the hardness of a simple Fe-C alloy changes as the carbon content is varied. Details the reasons behind the responses that you have sketched – ensuring you relate these to the relevant diagrams.

1. A practical method of doing the scale-up of cylindrical mixing tanks and agitator blades is to keep constant the power per unit volume of tank. It is desired to increase by 3 times the volume of a mixing tank. How should the tank diameter and stirrer speed change? Consider that the mixing tanks are geometrically similar. The power supplied to the agitator, P, can be considered as a function of the diameter of the agitator, D, its angular velocity, w, density, d, and viscosity, u, of the liquid.

At the beginning of the compression process of an air-standard Otto cycle, p1 = 1 bar, T1 = 290 K, V1 = 400 cm3. The maximum temperature in the cycle is 2200 K and the compression ratio is 8. Determine (a) the heat addition, in kJ. kJ (b) the net work, in kJ. kJ (c) the thermal efficiency. % (d) the mean effective pressure, in bar. bar (e) Develop a full accounting of the exergy transferred to the air during the heat addition, in kJ. Exergy In kJ Exergt Out: network kJ heat transfer kJ (f) Evaluate an exergetic efficiency for the cycle. % Let T0 = 290 K, p0 = 1 bar.

Draw & Label the typical fuel system for an engine that ony burns distillate fuel.

A two stage, single-acting compressor has a free air delivery of 4.2 m3/min when the ambient condition is 1.013 bar, 15oC.
• The suction pressure and temperature are 0.98 bar and 32oC respectively. • The air is compressed to 16 bar according to the law pv1.3 = C.
Assuming that the compressor is designed for minimum work with complete intercooling, calculate the indicated power required to drive the compressor.

Below are the control strategy of hydraulic hybrid vehicle. How can I modify code below to include the torque of motor of hydraulic hybrid vehicle? and How can I improve this

function [SOC,k,T_engine,S_engine,T_brake,T_pump] = strategy(duration,gamma,P,V,Pmin,Pmax,Vmin,Vmax,SOC,Disp,T_wheel,S_wheel,gearratio,S_map,Te_max,T_engine,S_engine,T_pm,k,eff_mech,eff_hyd)

S_flywheel = S_wheel*gearratio;
T_flywheel = T_wheel/gearratio;
T_brake = 0;

if SOC < 0.1
k=1; %Engine on
elseif SOC > 0.7
k=0; %Engine off
end

%T_pump +ve = charging
%T-pump -ve = discharging
if k==1
if T_engine*eff_mech < T_flywheel
  
%Engine provides full torque when hydraulic is insufficient to support
if SOC < 0.1
T_engine = T_flywheel/eff_mech;
Tmax = interp1(S_map,Te_max,S_engine);
if T_engine > Tmax
T_engine = Tmax;
end
end
  
T_pump = T_engine*eff_mech-T_flywheel;
  
elseif T_engine*eff_mech >= T_flywheel && T_flywheel >= 0
T_pump = T_engine-T_flywheel/eff_mech;
  
elseif T_engine*eff_mech >= T_flywheel && T_flywheel < 0
T_pump = T_engine-T_flywheel;
end
  
elseif k==0
T_pump = -T_flywheel;
T_engine = 0;
S_engine = 0;
end

%Stop charging when accumulator is full
if SOC >= 1 && T_pump > 0
T_pump = 0;
T_brake = -T_wheel;
end

%Including hydraulic efficiency
if T_pump > 0 %Charging thus real torque is smaller
T_pump = T_pump*eff_hyd;
elseif T_pump < 0 %Discharging thus requires higher real torque
T_pump = T_pump/eff_hyd;
end

%Torque of pump does not exceed its limit
if T_pump >= T_pm
T_brake = (T_pump-T_pm)*gearratio/eff_hyd;
T_pump = T_pm;
elseif T_pump <= -T_pm
T_pump = -T_pm;
T_brake = nan;
end

%Accumulator will charge to full
if SOC > 0.6
Qmax = (V-Vmin)/duration;
x_max = Qmax/(S_flywheel*Disp);
Tmax = P*Disp*x_max;
if T_pump > Tmax
T_pump = Tmax;
if T_brake == 0
T_brake = (T_engine*eff_hyd-T_pump)*gearratio/eff_hyd-T_wheel;
elseif T_brake > 0
T_brake = T_brake+(T_engine*eff_hyd-T_pump)*gearratio/eff_hyd-T_wheel;
end
end
end

x = T_pump/(P*Disp);
Q = S_flywheel*Disp*x*duration;

if Q == 0
SOC = SOC;
else
%V is volume of nitrogen gas; Q is rate of change of fluid pumped
V = V-Q;
SOC = (0.9*((Vmax/V)^gamma)-1)*Pmin/(Pmax-Pmin);
end

Your boss ask you to size a fun to transfer 50000 SCFM of air to ventilate a building 500 ft from the intended location of the fun. However, your boss has found an old fan and would like to reuse it if the specifications are compatibles with the project need. The identification plate shows: "design flow: 50000 SCFM and motor power 50 kW" Unfortunately, the value of the static pressure is unreadble because the identification plate is worn. Assuming that the friction loss in the pipe is one inch of water column, what would be the required power of the fun? mechanical efficience: 65% and 90% - fun and motor.

A 4 mm-diameter spherical raindrop falls freely in standard atmosphere. (a) Sketch a FBD and derive an equation for determining the terminal velocity. (b) Determine the terminal velocity. (c) Repeat (a) if the diameter is halved.

Fluid Mechanics Friction Problem: Write one MATLAB m-file that solves the Type I and II problems presented in class based on the file posted for the Type III problem (use Colebrook to estimate f). Type I: Solve hL for v=0.74x10-5ft^2/s, D=3 in, L=1000 ft, e=0.006 in, and Re=80000. f=0.0258 from Moody Chart. Type II: Solve Q for v=10^-6 m^2/s, D=0.2 m, L=500 m, e=0.046 mm, and hL=30m. Use “rough” Colebrook to generate an estimate for f.

If the time to failure distribution (PDF) is given by f(t) = gt^-4 (t > 2) and f(t) = 0 for t ? 2:

a) What is the value of g?

b) What is the mean time to failure?

c) What is the instantaneous failure rate?

What is a solid solution and what are the common types encountered in metals? Provide examples of common engineering alloys for each type (e.g. steel). Explain how a solid solution can help raise the strength of a metal. List some of the other methods of strengthening metals.

5) i) A two axes of an x-y positioning table are each driven by a stepping motor connected to a lead screw with a 10:1 gear reduction. The number of step angles on each stepping motor is 25. Each lead screw has a pitch = 7.5 mm and provides an axis range = 300 mm. There are 16 bits in each binary register used by the controller to store position data for two axes. (a) What is the control resolution of each axis? (b) What are the required rotational speeds and corresponding pulse train frequencies of each stepping motor in order to drive the table at 600 mm/min in a straight line from point (25,25) to point (100,150)?      (10)

ii) The designer of a polar configuration robot is considering a portion of the manipulator consisting of a rotational joint connected to its output link. The output link is 25 in long and the rotational joint has a range of 75 degrees. The accuracy of the joint-link combination, expressed as a linear measure at the end of the link which results from rotating the joint, is specified as 0.030 in. The mechanical inaccuracies of the joint result in a repeatability error= +-0.03 degrees of rotation. It is assumed that the link is perfectly rigid, so there is no additional error due to deflection. (a) Show that the specified accuracy can be achieved, given the repeatability error. (b) Determine the minimum number of bits required in the binary register of the robot’s control memory to achieve the specified accuracy.    (10)

A 5 kW split-phase motor running at 1750 rev/min is used to drive a rotary pump, which operates 24 hours per day. An engineer has specified a 200 mm small sheave, and 300 mm large sheave, and B3000 belts. The service factor was 1.3. Analyze the drive and estimate:
(a) center-to-center distance.
(b) suitable number of belts.
(c) F1, F2, Fc and Fi.
(d) the factor of safety.
(e) the belt life in passes