Prob. 2) A jet powered aircraft flies at a speed of 900 ft / s at an altitude of 20,000 ft, where the ambient conditions are 7 psia and 10 ° F. The pressure ratio in the compressor is 13 and the temperature at the inlet of the turbine is 2400 R. Assuming an ideal operation for all specific components and heats
constants for air at room temperature draw and graph the physical and T-S diagrams and determine:

a) the pressure at the outlet of the turbine and the thrust

b) the speed of the exhaust gases and

c) the propulsion efficiency.

Predicting Trends in Engine Performance

a) Write an expression for bmep in terms of the thermal efficiency, mechanical efficiency, volumetric efficiency, and combustion efficiency, as well as other engine design parameters. Group terms together that are related to engine thermochemistry, engine fluid mechanics, and engine kinematics/machine design. Identify each of these groupings.

b) Write an expression for the brake specific fuel consumption in terms of the mechanical efficiency, thermal efficiency, and combustion efficiency as well as the heating value of the fuel.

c) Reasoning with your equations, indicate the sign (+, -, or 0) of the likely change in bmep and also in bsfc based on modification of the design or operating parameter. Assume that all other design/operating conditions remain the same. Provide a short rationale for each answer.

- Increasing ambient temperature

- Decreasing ambient pressure

- Increasing engine displacement

- Increasing the air/fuel ratio

- Using a lower viscosity lubricant

- Improving intake/exhaust tuning

Prob.1) Consider a combined gas and steam power plant that has a net power output of 450 MW. The pressure ratio of the gas turbine cycle is 14. Air enters the compressor at 300 K and the turbine at 1 400 K. The combustion gases leaving the gas turbine are used to heat the steam to 8 MPa. up to 400 ° C in a heat exchanger. The combustion gases exit the heat exchanger at 460 K. An open feedwater heater is incorporated into the steam cycle operating at a pressure of 0.6 MPa. The condenser pressure is 20 kPa. Assuming that all compression and expansion processes are isentropic, graph the physical and T-S diagrams and determine:
a) the ratio of the mass air and steam flows,

b) the required rate of heat input into the combustion chamber and

c) the thermal efficiency of the combined cycle.

A cylindrical storage tank contains liquefied propane under a pressure of 1.5 MPa (gage pressure P=1.5 MPa) and is subjected to a torque T=5 kN-m. Knowing that the tank has an inner diameter of 320 mm and a wall thickness of 3 mm, find the principal stresses and determine the maximum shear stress.

To provide a service to a town, water is taken from a dam and raised to a tank from where it is distributed to the neighborhood. The difference in levels between the dam and the tank is 600 feet; the length of the commercial steel pipe is 40,000 feet and the required flow is 8,000 gpm. Define:
a) the necessary pumping station
b) The type of pumps
c) The turning speed
d) Diameter of impellers
e) Power necessary to provide this service.

Time-Based Preventive Maintenance and Condition-Based Preventive Maintenance are two methods that are used in maintenance. Explain your understanding of the application of each and provide three examples of each method. In addition, discuss which is more effective and optimal.

The purpose of OSHA’s standard for the control of hazardous energy is to protect people in the workplace (from this hazardous energy) while they are performing service or maintenance on plant machines and equipment. Hence, to prevent the accidental or inadvertent activation of systems, while it is being serviced or repaired, provide a framework, in a sequential order, of the procedure for use of the controls and lockout/tagout devices.

A mass (10 kg) is sitting on a table. The coefficients of static friction (.5) and kinetic friction (.2). A chain is attached to the box, frictionless, and is attached to a pulley at the end of the surface and a ball(5kg)is attached to the hanging end of the rope. The system is released from rest. Write the equations that correspond to each mass. Determine the magnitude of the acceleration of the boxes.

Compute diffusion coefficients for the interdiffusion of carbon in both (a) α-iron (BCC) and (b) γ-iron (FCC) at 875˚C. Assume that D0 for the interdiffusion of carbon in α-iron and in γ-iron are 1.1 × 10-6 and 2.3 × 10-5 m2/s, respectively, and that Qd are 80 and 148 kJ/mol, respectively. (a) m2/s (b) m2/s

Calculate the value of D at 636°C for the diffusion of some species in a metal for which the values of D₀ and Q_d are 5.9 × 10^-5 m²/s and 167 kJ/mol, respectively.

The activation energy for the diffusion of atomic species A in metal B is 113 kJ/mol. Calculate the diffusion coefficient at 859°C, given that the value of D at 1190°C is 7.3 × 10^-11 m²/s.

Determine the carburizing time necessary to achieve a carbon concentration of 0.50 wt% at a position 3.3 mm into an iron-carbon alloy that initially contains 0.18 wt% C. The surface concentration is to be maintained at 1.1 wt% C, and the treatment is to be conducted at 1050°C. Assume that D0 = 3.1 × 10-5 m2/s and Qd = 120 kJ/mol. The following table may be useful.

An iron-carbon alloy initially containing 0.227 wt% C is exposed to an oxygen-rich and virtually carbon-free atmosphere at 1080°C. Under these circumstances the carbon diffuses from the alloy and reacts at the surface with the oxygen in the atmosphere; that is, the carbon concentration at the surface position is maintained essentially at 0.0 wt% C. At what position will the carbon concentration be 0.170 wt% after a 9 h treatment? The value of D at 1080°C is 1.9 × 10^-10 m²/s.

Nitrogen from a gaseous phase is to be diffused into pure iron at 700°C. If the surface concentration is maintained at 0.19 wt% N, what will be the concentration (in weight percent) 2.3 mm from the surface after 7.5 h? The diffusion coefficient for nitrogen in iron at 700°C is 1.2 × 10^-10 m²/s.

describe a synchro self shifting (SSS) clutch and how it operates

The following are some maintenance strategies:

1. Breakdown (DEFECT /REACTIVE) Maintenance;

2. Preventive Maintenance;

3. Predictive Maintenance ;

4. Project Maintenance;

5. Proactive Maintenance

Provide a brief description of each of these strategies, then give examples of where each strategy would work best in real business and why you say so.

Please solve this question as soon as possible as it is part of an assignment that I have to submitt within 10 hours. Thank you.

Maximizar P=2x+3y+5z

Sujeto a: x+2y+3z ≤ 12

               x-3y+2z ≤ 10

                x ≥ 0, y ≥ 0, z ≥ 0

Maximize P=2x+3y+5z

Subject to:

x+2y+3z ≤ 12

x-3y+2z ≤ 10

                x ≥ 0, y ≥ 0, z ≥ 0

What is the typical impact energy value of the material for 3 different heat treatments (any). Put some microstructures and discuss the impact energy differences . For alluminium 6061