Considering the three classes of response of materials to changes in temperature, explain why it is a sudden change rather than an accelerating or gradual change that is important for the operation of a repeatable thermal cutout switch.

(a) Dry saturated steam at a temperature of 180ºC is to be produced in a fire tube boiler from the cooling of 50 000 kg h–1 of flue gases from a pressurised combustion process. The gases enter the tubes of the boiler at 1600ºC and leave at 200ºC. The feed water is externally preheated to 180ºC before entering the boiler. The mean specific heat capacity of the flue gases is 1.15 kJ kg–1 K–1. The latent heat of vaporisation of the water at 180ºC is 2015 kJ kg–1. Feed water temperature = 180ºC. Determine the amount of steam produced per hour, if the total heat loss is 10% of the heat available for steam raising.

(b) The overall heat transfer coefficient based on the outside area of the tubes is given as 54 W m–2 K–1. Determine the area of heat transfer required to perform this duty.

(c) The tubes within the boiler are to be 25 mm inside diameter with a wall thickness of 3 mm. The average flue gas velocity through the tubes to maintain the overall heat transfer coefficient value and to minimise pressure losses is to be more than 22 m s–1 and less than 28 m s–1. Assuming that the average density of the flue gases is 1.108 kg m–3, calculate:

(i) the minimum and maximum number of tubes in each pass

(ii) the overall length of tubes at each of these numbers of tubes

(iii) the minimum number of tube passes in each case, if the length of a boiler tube is to be less than 5 metres.

2. Write a program which reads in the text file generated in part one and writes out the same data as a comma-separated values (CSV) file for further processing.

The file should have a header line which identifies which column contains which values and should look something like this:
Time, Potentiometer, Temperature, Light, Switch0, Switch1, Switch2, Switch3
That header line should be followed by detail lines containing the measurements and should look something like this (matching the above Arduino output):
0,1,1,1,1,0.50,0.14,0.90 40,1,1,1,1,0.65,0.20,0.89

Store the data in an appropriate struct.

Small high-swirl direct-injection CI engines have fuel conversion efficiencies which are about 10 percent higher than values typical of equivalent indirect-injection engines. (ID1 engines are used because they achieve higher bmep.) What combustion-system-related differences contribute to this higher efficiency?

You are required to develop a computer code that that can solve systems of ODE. The code should request the user to choose one of the following methods for solving the system:

? Euler

? 4th Order Runge Kutta  

% Consider the following system of equations:
% -2a +5b + c + 3d + 4e - f = 0
% 2a - b - 5c - 2d + 6e + 4f = 1
% -a + 6b - 4c - 5d + 3e - f = -6
% 4a + 3b - 6c - 5d - 2e - 2f = 10
% -3a + 6b + 4c + 2d - 6e + 4f = -6
% 2a + 4b + 4c + 4d + 5e - 4f = -2

% a)
% Define a symbolic variable for each of the equation and use symbolic
% capability to solve for each unknown. Convert your results to doubles.

% Answer

% b)
% Compare the amount of time it takes to solve the system of equations
% using left division and symbolic math by using the tic and toc function.

% Answer

Explain how the use of glass walls gives rise to heating in a greenhouse. Be brief.

How Die-tools are traditionally manufactured. (should cover following information and no more than 300 words for each method) Your discussion in this section should include the following information regarding.

1. how method creates die and what materials can it use

2. what are the tolerances and finish of die

3. what are the material properties/strength of the final product

4. how long does it take to produce the desired die and approx cost.

5. Advantages and disadvantages.

Moist air enters an adiabatic humidifier system at 1 atm, 15 °C, with a relative humidity of 20%. The volumetric flow rate of the incoming moist air is 150 m3/min. Saturated water vapor at 1 atm is injected into the flow such that the outlet temperature is 30 °C and the outlet relative humidity is 40%. The pressure is constant in the humidifier system. Determine the mass flow rate of the saturated water vapor entering the humidifier at state 3, in kg/min. Note: The molar mass of air is 28.97 kg/kmol and the value of the universal gas constant is R¯ = 8.314 kJ/(kmol*K)

The rotor of a kaplan turbine is 2.8m in dia. at the blade tips and 0.9m at the hub. Its speed of rotation is 110r/min. Water enters the rotor without shock, making an angle of 37° to the axial direction at the mean dia and rotor has a blade exit angle of 58° to the axial direction at the mean diameter. The available pressure head is 6.5m .Determine 1) the inlet angle of the rotor blades at the mean dia. 2) the hydraulic efficiency and 3) the maximum mechanical power developed if the mechanical efficiency is 95%. make a neat drawing showing the layout and dimensions of the turbine and draw the inlet and exit velocity diagrams reasonably to scale

A hydro power station is required to deliver 48MW of power to the national grid from a site where the available head is 16m The alternator efficiency may be taken as 96%.The proposed rotational speed of the coupled turbo-alternators is 150r/min and the specific speed of the available turbines is 400. Estimate the number 9f units required

Obtain manufacturers’ data on thermocouple and thermistor temperature sensors for measuring temperatures of hot combustion gases from a furnace. Explain the basic operating principles of each sensor and compare the advantages and disadvantages of each device. Consider sensitivity, accuracy, calibration, and cost.

For water in state 1.5 bar, 225 C, what is the specific internal energy of water (kJ/kg)?

Does the force of compaction in powder metallurgy affect final part properties? How?