Water ( ρ= 1000 kg/m3; Cp= 4.2 kJ/kg.K) at 1,488 kg/hr and 13oC enters a 10-mm-diameter smooth tube whose wall temperature is maintained at 56oC. If the convection heat transfer coefficient is 11,496 W/m2.K, calculate the tube length, in m, necessary to heat the water to 40oC.

Draw moving sound wave and stationary sound wave coordinate system.
From fundamental principles derive speed of sound. Calculate speed of sound in water and iron.

A Food storage locker requires a refrigeration system of 42kW(12TR) capacity at an evaporator temperature of -5°C and condenser temperature of 40°C. The refrigerant, R-12, is sub-cooled 5°C before entering the expansion valve, and the vapour is super-heated 6°C before leaving the evaporator coil. The compression of the refrigerant is isentropic. A two-cylinder vertical single acting compressor with stroke equal to 1.5 times the bore is to be used operating at 960 r.p.m. Determine (i) refrigerating effect/kg. (ii) mass of refrigerant per minute, (iii) theoretical suction volume per minute (iv) theoretical power, (vi) COP, (vi) heat removed through condenser/kg and (vii) theoretical bore and stroke of compressor.

The pressure and temperature at the beginning of the compression are 1 bar and 27°C. Assuming an ideal engine in which the compression ratio and the expansion ratio for a C.I engine are (15+ ? ???) and (8− ? ???) respectively. Determine the mean effective pressure, the ratio of maximum pressure to mean effective pressure and cycle efficiency. Also, find the fuel consumption per kWh if the indicated thermal efficiency is 50% of ideal efficiency, mechanical efficiency is 80% and the calorific value of diesel oil is 42000 kJ/kg. Assume for air: cp = 1.005 kJ/kg K ; cv = 0.718 kJ/kg K, γ = 1.4. [7 Marks] Where n is 17

Suppose the thickness of a certain part is important to a major customer. You want to know how “good” the micrometer you use is, i.e., is the measurement system acceptable? You decide to run a Gage R&R by having 3 operators measure 5 parts 2 times each. You perform the Gage R&R using operators A, B and C. The data from the study are given in Table 1 below. Perform the Gage R&R study and interpret the results.

Table 1: Gage R&R Data

Operator Part Trial 1 Trial 2

A 1 170 158

A 2 212   208

A 3 190 178

A 4 192 193

A 5 159 145

B 1 158 153

B 2 209 194

B 3 187 175

B 4 187 175

B 5 147 138

C 1 155   151

C 2 208 200

C 3 182 178

C 4 185 179

C 5 150 149

Water flows over a horizontally standing plate. The length of the plate is 1.5 m and its temperature is constant and at 15 ° C. d. The temperature of the water flowing over the plate is 75 ° C and its speed is 0.11 m / sec. According to this, a.) Calculate the speed and temperature boundary layer thickness at the end of the plate. b.) Find the local heat transfer coefficient and heat flux at the end of the plate. c.) Find the average heat transfer coefficient and heat flux at the end of the plate.

Made of steel (ρ = 7920 kg / m3 cp = 580 J / kg ° K, k = 52 W / mK) with a diameter of 70 mm and a length of 8000 mm The rod is first kept in a room with an ambient temperature of uniform 40 ° C. Rod then film coefficient It enters its oven of 373 W / m2K at 900 ° C. After 2273 seconds, a.) Find the center axis temperature of the rod? b.) How much heat is passed into the bar during this time?

discuss the connectors and cabling which are used in industrial Ethernet

A 30 kW ammonia compressor (ˠ = 1.2) operates with an evaporator and condenser temperatures of 10 C & 40 C, respectively. The clearance factor is 5% with compression or adiabatic efficiency 85%, mechanical efficiency 80% & actual volumetric efficiency 75%.
Determine:
a. Draw the PH diagram indicating all enthalpy & sp. vol.
b. Clearance volumetric efficiency
c. Actual work, kJ/kg
d. Ideal COP
e. Actual COP
f. Mass of refrigerant flow, kg/s
g. Indicated work, kW
h. Brake work, kW

Nitrogen (N2) goes through a constant area pipe (see figure below) at a mass rate of 2 kg/s. It enters the pipe with a velocity of 17 m/s, a pressure of 500 kPa and a temperature of 177 C. It leaves the pipe at the same pressure (500 kPa) and a temperature of 67 C. The molar mass of N2 is 28 kg/kmol. Determine: a) The cross sectional area of the pipe in m2 . b) The velocity at the exit side in m/s. c) The rate of heat transfer in kW between the pipe and the surroundings. Also, indicate its direction.

A 4-cylinder ammonia compressor with a bore 0.04 m & stroke 0.03 m running 2500. The system operates in a simple VCC with evaporating & condensing temperatures zero C & 40 C, respectively generating cooling capacity 5 tons.
Determine:
a. Draw the PH diagram indicating all enthalpies & sp. vol.
b. Piston displacement, m3/sec
c. Suction Volume, m3/sec
d. Volumetric efficiency
e. Mass of refrigerant, kg/sec
f. Work of compressor, kW

Machine A was purchased three years ago for $23,000 and had an estimated MV of $2,300 at the end of its 10-year life. Annual operating costs are $2,300. The machine will perform satisfactorily for the next seven years. A salesperson for another company is offering Machine B for $57,000 with an MV of $5,500 after 10 years. Annual operating costs will be $1,500. Machine A could be sold now for $17,000, and MARR is 15% per year. Compare the before-tax equivalent uniform annual cost, EUAC, of the defender (keeping Machine A) to the challenger (buying Machine B). To answer this problem, calculate the value of the difference in annual costs; EUAC(challenger) – EUAC(defender) = EUAC(Machine B) – EUAC(Machine A). (Enter your answer as a number without the dollar $ sign.)

Why does not baitite occur in the continuous cooling transformation diagram?

Think about a turboprop engine (explained in the lecture). The turbine-compressor assembly drives a propeller for the propulsion and it delivers net power of 1.1 MW to the prop. This aircraft was designed to fly at 8km altitude with 550 km/h speed. The atmospheric condition up there is 236K and 0.36 bar. Air enters the diffuser and decelerates to 0 km/h for maximizing the ram effect. The compression ratio is 6.3 and the isentropic efficiency of the compressor is 83%. The turbine has 1360K inlet temperature, and the efficiency is also 83%. The pressure at the turbine exit is 10 kPa higher than the ambient pressure, and assume that the diffuser and nozzle show isentropic behaviors. Kinetic energy except for at the diffuser and the nozzle exit can be neglected. Determine:

a) The mass flow rate in kg/s.

b) The volumetric flow rate in m³/s.

c) The heat rate produced in the combustion in W.

d) The gas velocity leaves the nozzle in m/s.