Liquid phenol at 298 k, 100kPa is burned with 152% theoretical air at 295k, 100kPa. Determine the adiabatic flame temperature. Enthalpy of liquid phenol is given as -96,232 kJ/kmol

a four bar mechanism has the following dimensions. DA=300mm, CB=AB=360mm DC=600mm. the link DC is fixed and the angle ADC is 60⁰. The driving link DA rotates uniformly at a speed of 100rpm clockwise and the constant driving torque has a magnitude of 50 N-m. Determine the velocity of the point b and angular velocity of the driven link cb

1. Ammonia is initially at a temperature of -10° C and a specific volume of 0.07 m3/kg. The ammonia undergoes an isobaric expansion to a final specific volume of 0.22 m3/kg. Evaluate the specific work done on the ammonia in kJ/kg and the specific heat transfer to the ammonia in kJ/kg. Neglect changes in kinetic energy and potential energy.

2. Carbon dioxide is contained in a piston-cylinder assembly with an initial pressure and temperature of 8 lbf/in2 and 100° F, respectively. The carbon dioxide has a mass of 0.05 lb. The carbon dioxide is expanded isothermally to a final volume of 1 ft3. Model the carbon dioxide as an ideal gas with constant specific heats. Evaluate the specific heats at 100° F. Determine the amount of work done on the gas in Btu and the heat transfer to the gas in Btu. Neglect changes in kinetic energy and potential energy.

3. An ideal gas with constant specific heats undergoes a process from an initial pressure and specific volume of 80 kPa and 40 m3/kg to a final specific volume of 20 m3/kg. During the process, the hydrogen’s pressure and specific volume are related through the equation given below. In the equation, ?? and ?? are the initial pressure and specific volume of the hydrogen, respectively. Determine the specific work done on the gas in MJ/kg and the specific heat transfer to the gas in MJ/kg. The ideal gas has a molar mass of 2.0 kg/kmol and a specific heat at constant volume of 7.5 kJ/(kg∙K). Neglect changes in kinetic energy and potential energy.

   ? = ?? ⋅ [2 − (?/??)]

Consider a two-stage cascade refrigeration system operating between the pressure limits of 1.2 MPa and 200 kPa with refrigerant R717 (Ammonia) a as the working fluid. The refrigerant leaves the condenser as a saturated liquid and is throttled to a flash chamber operating at 0.45 MPa. Part of the refrigerant evaporates during this flashing process, and this vapor is mixed with the refrigerant leaving the low-pressure compressor. The mixture is then compressed to the condenser pressure by the high-pressure compressor. The liquid in the flash chamber is throttled to the evaporator pressure and cools the refrigerated space as it vaporizes in the evaporator. The mass flow rate of the refrigerant through the low-pressure compressor is 0.15 kg/s. Assuming the refrigerant leaves the evaporator as a saturated vapor and the isentropic efficiency is 80 percent for both compressors, determine (a) the enthalpy at the exit of the high pressure compressor, (b) the entropy at exit of low pressure compressor , (c) the mass flow rate of the refrigerant through the high-pressure compressor, (d) the rate of heat removal from the refrigerated space, and (e) the COP of this refrigerator. Also, determine (f) the rate of heat removal and (g) the COP if this refrigerator operated on a single-stage cycle between the same pressure limits with the same compressor efficiency and the same flow rate as in part (c)

6. (a) Name a conductor, an insulator, a semiconductor, a ductile material and a brittle material.

(b) Why does a typical conductor show a relatively high electrical conductivity and a high ductility at room temperature? Comment on its electrical conductivity when it is heated.

(c) Derive the units of ductility and electrical conductivity.

NASA has created a heat engine which operates between the sun and the vacuum of the space where the
temperature is absolute zero. He says that his engine is nearly 100% efficient. Do you agree with the claim
assuming the engine to be totally reversible? Analyse the scenario using equation for efficiency of Carnot
engine and Kelvin statement to evaluate your conclusion.

) A 50 mm-diameter propeller was installed in a 150 mm-diameter water pipe and the propeller speed was measured for a range of water discharge in the pipe. The water had a density and dynamic viscosity of 1000 kg/m³ and 0.00112 Ns/m² respectively. The measured results were as follows:

Plot the dependence of propeller coefficient against propeller Reynolds number. A geometrically similar propeller with diameter 100 mm was installed in a 300 mm-diameter pipe conveying oil with density 800 kg/m³ and dynamic viscosity 0.007 Ns/m² . Estimate the discharge in the oil pipe for measured propeller speeds of 40 rps and 90 rps.

Air at 20°C and 1 atm flows over a spherical object at 1 m/s. The sphere has a diameter of 10mm and its initial temperature is 134°C. If the density, specific heat, and conductivity of the sphere are 7832 kg/m”, 549 J/kg.K, and 49.2 W/m.K, respectively, calculate the temperature at the center of the sphere after 100 seconds.

The whey obtained from centrifugation to extract some proteins is stored in a preliminary tank and subsequently pumped at a rate of 20 L / s to the general storage tanks, to be used in other processes. The starting tank and the storage tank are kept at atmospheric pressure and the difference of 10 m in height that exists between the whey in each tank is constant. The total length of pipe in the suction line is 5 m with a standard 4-inch diameter and absolute roughness equal to 0.00125 m. The discharge length is 25 m with a diameter of 6 in and the same roughness. Consider the vapor pressure of the whey similar to that of water at 30 ° C (4243 Pa).

The density of the whey at operating conditions is 1027 kg / m3
The viscosity of the whey can be considered 0.0012 Pa * s.
The valves and accessories that are installed in the system's piping system are:
Accessory type

Resistances (K) for each accessory

2 Standard 90 ° elbows = 0.75

1 gate valve at the pump outlet = 0.17

1 globe valve fully open at the pump inlet = 10

Centrifugal tank inlet to pipeline = 0.5

Inlet from storage tank to pipeline = 0.6

Determine the following parameters:
a) Fluid velocity in the piping system (suction and discharge)
b) Energy losses due to friction in pipes (suction and discharge)
c) Reynolds number (suction and discharge).
d) Value of the friction factor (suction and discharge).
e) Friction energy losses in valves and accessories (suction and discharge).
f) Determine the NPSH available and required for the system
g) Pressure drop in the system.
h) Dynamic load of the system that the pump must deliver to propel the fluid from section A to section B shown in the figure.
i) The power received by the liquid, supplied by the pump.
j) The motor power, considering an efficiency of the motor-pump set of 60%.

A solid shaft is designed to twist no more than an angle of 2º when subjected to a torque of 800 Nm. The shaft is 1 m long and made from a material that has a shear modulus, G = 70 GN/m². Select an appropriate minimal diameter for the design specifications if

1. Solid shaft was used.
2. Hollow shaft of wall thickness 5mm was used.
3. If the shaft is to rotate at 2000 rpm, determine the maximum power that can be transmitted by the HOLLOW shaft.

1. Hot forging is used to reduce a metallic cylindrical workpiece with a diameter of 12 cm and height of 24 cm to a height of 15 cm. The coefficient of friction of the open die plate with the workpiece is 0.18 and the process takes 4 seconds to complete and at a constant speed. The strength coefficient of the workpiece C= 180 MPa and strain rate sensitivity exponent m = 0.25. calculate the following:

1. The forging shape factor at the end of the process.
2. The maximum flow stress (MPa).
3. The maximum forging force (N).
4. The power (W) required to complete the process.

3. In a Rankine cycle, the water enters the turbine at a pressure of L = 15 MPa and M = 525 ° C. Condenser pressure is N = 10 kPa. At the condenser outlet, it is assumed that the water is saturated liquid and the pump inlet pressure is again N = 10 kPa. Since the isentropic efficiency of the pump is Y 80%, the isentropic efficiency of the turbine is Z = 60%,
a-) Calculate the heat given to the loop in the boiler. (10 s)
b-) Calculate the net work of the loop. (10 s)
c-) Find the thermal efficiency of the loop. (10 s)

Air enters the diffuser of a turbojet engine at 18 kPa, 216 K, with a volumetric flow rate of 230 m³/s and a velocity of 265 m/s. The compressor pressure ratio is 15, and its isentropic efficiency is 87%. Air enters the turbine at 1560 K and the same pressure as at the exit of the compressor. The turbine isentropic efficiency is 89%, and the nozzle isentropic efficiency is 97%. The pressure at the nozzle exit is 18 kPa. Use an air-standard analysis.

a)

Determine the rate of heat input to the combustor, in MW.