The logarithmic wind profile assumes horizontal homogeneity and temporal stationarity. Give two examples how those assumptions might be violated here.

Problem 2: In Multi-Effects Desalination (MED) system composed of 4 effects, and 3 feed preheaters and down condenser. List the following: a- The mass balance in the evaporator, feed preheater and down condenser b- The energy balance in the evaporator, feed preheater and down condenser c- The Material balance in the first effect d- The temperature profile of the feed if the intake temperature is 25ºC and temperature of last effect is 40ºC and the temperature of first effect is 60ºC e- What will happen to the transfer area of the evaporator if the motive steam temperature is increased to 100ºC where the rest is remaining constants.

A refrigerator using R-12 as the working fluid

keeps the refrigerated space at 2158C in an environment at

308C. You are asked to redesign this refrigerator by replacing

R-12 with the ozone-friendly R-134a. What changes in the

pressure levels would you suggest in the new system? How

do you think the COP of the new system will compare to the

COP of the old system?

- What is the difference between MED and MSF desalination technology? If you have low grade heat source (Temperature is less than 70ºC) which one is more efficient?

To compare between different desalination system different criteria have been used such as: Performance Ration (PR), Gain Output Ratio (GOR), Specific Energy Consumption (kWh/m3 ) and Unit Product Cost ($/m3 ). Define each one and on your opinion which criteria are considered most useful?

Possible reasons and benefits of using robots in this application (Material handling/ Processing operations/ Assembly and Inspection)

Based on the reading assignment and the textbook, answer the following questions:

a- The impact of increasing the number of effects in MED system on the performance ratio (PR)? And list the reasons (10 Points)

Ideal Reheat Steam Cycle (10)

Consider a steam power plant operating on the ideal reheat Rankine cycle. Steam enters the high-pressure turbine at P_H MPa and T_H °C and is condensed in the condenser at a pressure of P_L kPa. Assume the steam is reheated to the inlet temperature of the high-pressure turbine, and that pump work is NOT negligible. If the moisture content of the steam at the exit of the low-pressure turbine is not to exceed w_% percent, determine:

(a) the pressure at which the steam should be reheated ,

(b) the total turbine work ,

(c) the net work ,

(d) the total heat input , and

(e) the thermal efficiency of the cycle .

P_H = 12.5 MPa, T_H = 550 °C, P_L = 30 kPa and w_% = 11.4%.

Course: Mechanical Vibration

Report Paper ( 1000 words)

Topic is Shakers for Aircraft Suspension Durability Testing

All material must be referenced correctly. Reference could be from Journals, Articles, Books.

Please include at least 2 or 3 reference.

Consider a steam power plant operating on the ideal reheat Rankine cycle. Steam enters the high-pressure turbine at P_H MPa and T_H °C and is condensed in the condenser at a pressure of P_L kPa. Assume the steam is reheated to the inlet temperature of the high-pressure turbine, and that pump work is NOT negligible. If the moisture content of the steam at the exit of the low-pressure turbine is not to exceed w_% percent, determine:

(a) the pressure at which the steam should be reheated ,

(b) the total turbine work ,

(c) the net work ,

(d) the total heat input , and

(e) the thermal efficiency of the cycle .

P_H = 15 MPa, T_H = 650 °C, P_L = 7.5 kPa and w_% = 9.4%.

A simple steam power cycle contains a turbine, condenser, pump and a boiler. If the turbine inlet pressure is 14 MPa and 600 °C, and the Condenser Inlet Pressure is 18 kPa, calculate the following:

1. Turbine Inlet Enthalpy (kJ/kg)
2. Condenser Inlet Enthalpy (kJ/kg)
3. Condenser Inlet Temperature (°C)
4. Pump Inlet Enthalpy (kJ/kg)
5. Boiler Inlet Enthalpy (kJ/kg)
6. Boiler Inlet Temperature (°C)
7. Turbine Work Output (kJ/kg)
8. Boiler Heat Addition (kJ/kg)
9. Net Work Output (kJ/kg)
10. Efficiency of the Cycle (%)

Work as accurate as possible. For each correct answer you receive 1 Mark, thus 10 Maximum. Choose the most appropriate answer from the lists, and then continue with the chosen answer in order to have your calculations as accurate as possible.

A simple steam power cycle contains a turbine, condenser, pump and a boiler. If the turbine inlet pressure is 14.5 MPa and 550 °C, and the Condenser Inlet Pressure is 19 kPa, calculate the following:

1. Turbine Inlet Enthalpy (kJ/kg)
2. Condenser Inlet Enthalpy (kJ/kg)
3. Condenser Inlet Temperature (°C)
4. Pump Inlet Enthalpy (kJ/kg)
5. Boiler Inlet Enthalpy (kJ/kg)
6. Boiler Inlet Temperature (°C)
7. Turbine Work Output (kJ/kg)
8. Boiler Heat Addition (kJ/kg)
9. Net Work Output (kJ/kg)
10. Efficiency of the Cycle (%)

Work as accurate as possible. For each correct answer you receive 1 Mark, thus 10 Maximum. Choose the most appropriate answer from the lists, and then continue with the chosen answer in order to have your calculations as accurate as possible.

A converging-diverging rocket nozzle is connected to a combustion chamber filled with gas at a total pressure of 1200 kPa and a total temperature of 2400 K. The design exit Mach number is 2.9 and the nozzle throat area is 50 cm2 . Assume the gas behaves as an ideal gas with k = 1.3 and a molecular weight of 24 kg/kmol. Determine (a) The back pressure necessary to induce the design Mach number at the nozzle exit. (b) The design exit area for isentropic supersonic flow. (c) The static pressure at the throat when the flow is choked. (d) The mass flow rate through the nozzle when the flow is choked.