PD control

1. The equation of motion for the DC motor are given by the equation:

J ¨?m + (B + KbKT Ra ) ? ?m = KT Ra Va (2)

where: J = 0.01kg · m2 , B = 0.001N · m · s, KT = 0.02N · m/A, Kb = 0.02V /s and Ra = 10?.

(a) Suppose that feedback is added to the system to achieve position control of the motor shaft. Given a desired shaft position ?r (the reference), the applied voltage is given by a proportional controller:

Va = K(?r ? ?m) (3)

Where K is the feedback gain. Find the transfer function from ?r to ?m

(b) Can you find some value of K that provides a rise time of less than 4 seconds and keeps the system overshoot less than 20%? Why?

(c) If cannot (for question 2b), can you design a new controller that achieve all the requirements in question 2b? Write down your controller and show any work involved.

Discuss the meaning/importance in 2-3 sentences per term:

(1) Beach or clamshell marks; (2) Chevron pattern; (3) Creep; (4) Endurance limit; (5) Factor of safety; (6) Fatigue life; (7) Fatigue strength; (8) Fracture mechanics; (9) Fracture toughness; (10) Griffith law; (11) Notch sensitivity; (12) S-N curve; (13) Shot peening; (14) Toughness; (15) Weibull distribution; (16) Weibull modulus.

Note: Make sure please to type the answers briefly and clearly.

1-What are the three configuration types of stereoisomers? Sketch portions of a linear polymer molecule that clearly shows each of those three types.

2-What are the two types of geometric isomers? Sketch structures for each of those types using a polymer

Explain the difference between heat treatable aluminum alloys and work hardenable aluminum alloys. Which is more easily cold worked? Why?

One kilogram of Refrigerant 134a vapor initially at 2 bar and 20°C fills a rigid vessel. The vapor is cooled until the temperature becomes -24°C. There is no work during the process.

Let T_o = 20°C, p_o = 0.1 MPa and ignore the effects of motion and gravity.

2. For the refrigerant, determine the change in exergy, in kJ.

Note: for part 1: q=-98.086kj please find part two- the change in exergy in kj

Calculate the number of cycles to failure (Nf) of an aluminum alloy exposed to reverse tensile-compressive loading (N) with a stress amplitude of 150MPa.   A = 2x10^-12.   n = 2.5m.

If initially the length (ao) of the largest crack is 0.75mm and the fracture toughness (Kc) = 35MPA m1/2.   

What are the unique PLM needs for a small and medium company? 1000-1500 words

3 Kg mass of water is heated to a temperature of 99.5 C at 1 bar of pressure. It is slowly poured into a heavily insulated beaker containing 7.5 Kg of water at a temperature and pressure of 4 C, 1 bar, respectively. The specific heat of the water, an incompressible material is, c = 4.1 KJ/(Kg K). The beaker can be considered to be an adiabatic system. The two water mass’ reach an equilibrium temperature. There is no kinetic or potential change in this problem. The dead state pressure is defined as P_o = 1 bar. Instead of mixing the two fluids together consider the following proposal. Heat is allowed to flow from the 3 Kg mass of water through a Carnot heat engine and is rejected to the surroundings. Determine the maximum amount of work that could be performed, and the exergy destroyed during the operation.

In this case the temperature and internal energy of the mass of water is changing unlike the infinite heat reservoir case.Since the temperature of the high temperature heat input is changing the Carnot efficiency is also changing.In order to account for this change, you should consider using an energy balance for every 5 C change in the temperature of the 3Kg water mass and calculate the Carnot efficiency at the average temperature.For example, in the first numerical step the temperature of the water mass would change from 99.5 to 94.5 C and the Carnot efficiency for this temperature step would be T = 370 K.You should determine the incremental work done during this step with an energy balance on the heat engine. The exergy destruction is calculated in a similar incremental manner.

(a) Calculate the work output and entropy production when the 3 Kg mass of water is brought into equilibrium with surroundings at 4 C.

(b)Compare the exergy destroyed between the mixing process and the heat engine process.

1) Explain how different engine operating conditions affect combustion ( ignition delay, temperatures, air fuel ratio, speed, heat transfer)?

2) What are the 3 sources of NOX formation, which is the least relevant, which is the most relevant, explain why?

What are austenitic steels? Write about their a) alloy principles b) effects of alloys (mechanical and radiation properties)

Provide references, please.

Many sports cars are convertibles. The air flow over such a car is significantly different depending on whether the convertible top is up or down. The engine of the 1000-kg car delivers 135 kW to the wheels, the car frontal area is 1.9 m² and rolling resistance is 2.5% of the car weight. The drag coefficient when the top is down is 0.43 and 0.31 when it is up. For 20 ºC air at one atmosphere, determine:

a. the maximum speed with the top up (in m/s)

b. the maximum speed with the top down (in m/s)

A design related question.

1)design a walk in refrigerator and freezer with 10 ton and 30 ton cooling capacity respectively.
2) freezer must be maintained between (24 to 15 deg celcius) and refrigerator between (3-7 deg celcius)
3)ambient condition ( 38 deg celcius) and refrigeration compressor efficiency assumed at 75%.
4)heat exchanger maintained at 11 deg celcius.
5) emphasis on reducing operating cost, so one compressor can be used and also flash chamber
6) reducing compressor work input and increasing coefficient of performance.
7) power consumption must be in Kilowatt ( KW).

how would you do this?
can you write why you went with the choice you went with...just summarize and justify your findings. it's a open ended question and there is no right or wrong answer.

thank you, looking forward to learning this.

A project requires weighing and dispensing of multiple hi-potent (ECL>3) pharmaceutical compounds in powder form for a blockbuster, commercially marketed drug, it’s a sterile processing plant. Provide your conceptual HVAC design description that include primary enclosures (only HVAC for handling and transfer devices) and secondary (room/HVAC) containments to protect product attributes (integrity, efficacy, purity), personnel from environmental exposures. Elegant, energy efficient, and least cost design URS solution are required criteria. A project requires weighing and dispensing of multiple hi-potent (ECL>3) pharmaceutical compounds in powder form for a blockbuster, commercially marketed drug, it’s a sterile processing plant. Provide your conceptual HVAC design description that include primary enclosures (only HVAC for handling and transfer devices) and secondary (room/HVAC) containments to protect product attributes (integrity, efficacy, purity), personnel from environmental exposures. Elegant, energy efficient, and least cost design URS solution are required criteria.

A combined cycle power system uses a simple gas-turbine Brayton cycle in conjunction with a simple Rankine cycle to produce a total power of 100 MW. In such configuration, the exhaust stream from the gas turbine is used as the heat source for the steam power cycle in a heat exchanger as shown in the figure. The following data are known for the gas-turbine cycle. Atmospheric air enters the compressor at 100 kPa and 20oC, the compressor pressure ratio is 8, the compressor isentropic efficiency is 85%, the maximum gas cycle temperature is 1100oC, and the gas turbine isentropic efficiency is 90%. Additionally, it is known that the gas stream leaves the heat exchanger at the saturation temperature of the steam flowing through it. The following data are known for the steam-turbine cycle. Steam flows through the heat exchanger with a pressure of 6000 kPa, leaving at 320oC, the steam-cycle condenser operates at 20 kPa, and the isentropic efficiency of the steam turbine is 90%.

(a) Schematically draw the complete system including all the equipment required for the analysis. Additionally, sketch the corresponding thermodynamic diagrams for the Brayton and Rankine cycles involved. Assign a different number to each stream and use such number in the diagrams.

(b) Find the power generation efficiency of the gas-turbine.

(c) Find the power generation efficiency of the Rankine cycle.

(d) Find the steam-turbine power, the gas-turbine power, and the total efficiency of the combined cycle.