PRE BOARD PIPE 8

50問 • 1年前

問題一覧

A frictionless piston-cylinder device and a rigid tank contain 1.2 kmol of ideal gas at the same temperature, pressure and volume. Now heat is transferred, and the temperature of both system is raised by 15 deg. C. the amount of extra heat that must be supplied to the gas in the cylinder that is maintained at constant pressure.

150 KJ

An insulated rigid tank initially contains 1.5 lb of helium at 60 deg F and 50 psia. A paddle wheel with power rating of 0.02 hp is operated within the tank for 30 min. Determine the final temperature.

179.22 deg. F

A 4 m^2 asphalt pavement with emissivity of m0.85 has a surface temperature of 50 deg. C. Find the maximum rate of radiation that can be emitted from the surface.

2,098.32 watts

An aluminum pan whose thermal conductivity is 237 W/m-C has a flat bottom whose diameter is 20 cm and thickness 0.4 cm. heat is transferred steadily to boiling water in the pan through its bottom at a rate of 500 watts. If the inner surface of the bottom of the pan is 105 deg. C, determine the temperature of the surface of the bottom of the pan

105.27 deg. C

For a heat transfer purposes, a standing man can be modeled as a 30 cm diameter, 170 cm long vertical cylinder with both the top and bottom surfaces insulated and with the side surface at an average temperature of 34 deg. C. for convection heat transfer coefficient of 15 W/m^2-C, determine the rate of heat loss from this man by convection in an environment at 20 deg. C.

336.46 watts

A 5 cm diameter spherical ball whose surface is maintained at a temperature of 70 deg. C is suspended in the middle of a room at 20 deg. C. if the convection heat transfer coefficient is 15 W/m^2-C and the emissitivity of the surface is 0.8, determine the total heat transfer from the ball.

32.77 watts

105.27 deg. C

A 4 m^2 asphalt pavement with emissivity of m0.85 has a surface temperature of 50 deg. C. Find the maximum rate of radiation that can be emitted from the surface.

2,098.32 watts

179.22 deg. F

Air at 300 deg. K and 200 Kpa is heated at constant pressure to 600 deg. K. determine the change of internal energy.

215.58KJ/kg

Air flows through a nozzle with temperature of entrance of 420 deg. K stagnation temperature of 468 deg. K. find the mach number.

0.744

Air enters a diffuser with a velocity of 200 m/s. determine the velocity of sound if air temperature is 30 deg. C

369 m/s

Carbon dioxide flows through a nozzle with a speed of 380 m/s. The entrance condition of nozzle is 250 deg. C and 1200 Kpa. Find the stagnation pressure.

2,136.34Kpa

Carbon dioxide flows through a nozzle with a speed of 400 m/s. Compute the dynamic temperature.

94.56 K

Air flows through a nozzle at a speed of 350 m/s. Find the stagnation temperature if entrance temperature is 200 deg. C

261.25 deg C

Steam flows through a nozzle at 400 deg. C and 1 Mpa (h = 3263.9 KJ/kg) with velocity of 300 m/s. find the stagnation enthalpy.

3309 KJ/kg

Water flowing at the rate of 10 m/s from an orifice at the bottom of a reservoir. Find the pressure at the bottom of reservoir.

50 Kpag

A 300 mm diameter pipe discharges water at the rate of 200 li/s. point 1 on the pipe has a pressure of 260 Kpa and 3.4 m below point 1 is point 2 with a pressure of 300 Kpa. Compute the head loss between points 1 and 2.

1.87 m

What force is exerted by water jet 60 mm diameter if it strikes a wall at he rate of 15 m/s?

636.17N

The type of flow occupying in a 1 cm diameter pipe which water flows at a velocity of 2.50m/s. Use v = 1.13 x 10^- 6 m^2/s for water.

Turbulent

Determine the size of pipe which will deliver 8 liter of medium oil (c = 6.10 x 10 ^-6 m^2/s) assuming laminar flow conditions

835 mm

A cylindrical pipe with water flowing downward at 0.03 m^3/s having top diameter of 0.08, bottom diameter of 0.04 m and height of 1.5 m. find the pressure between the pipe.

252.44 Kpa

An empty, open can is 30 cm high, with a 15 cm diameter. The can with the open end down is pushed under water with a density of 1000 kg/m^3. Find the water level in the can when the top of the can is 50 cm below the surface.

12.12 cm

A liquid dominated geothermal plant with a single flash separator receives water at 204 DegC. The separator pressure is 1.04 Mpa. A direct contact condenser operates at 0.034 Mpa. The turbine has a Polytropic efficiency of 0.75 for a cycle output of 60 MW, what is the mass flow rate if the wall-water in kg/s?

2,933

18,000 KW geothermal plant has a generator efficiency and turbine efficiency of 90% and 80%, respectively. The quality after throttling is 20% and each well discharges 400,000 kg/hr, determine the number of wells are required to produce if the change of enthalpy at entrance and exit of turbine is 500 kj/kg.

2 wells

A steam turbine with 80% stage efficiency receives steam at 7 Mpa and 550 DegC and exhaust as 20 Kpa, determine the quality at exhaust.

96.96%

A steam turbine with 85% stage efficiency receives steam at 7 Mpa and 550 degC and exhaust as 20 Kpa. Determine the turbine work.

1,054.95Kj/kg

A steam turbine receives 5,000 kg/hr of steam at 5 Mpa and 400 DegC and velocity of 30 m/sec. It leaves the turbine at 0.006 Mpa and 85% quality and velocity of 15m/sec. radiation loss is 10,000 Kj/hr. find the KW developed.

1373.60

A 350 mm x 450 mm steam engine running at 280 rpm has an entrance steam condition of 2 MPa and 230 degC and exit 0.1 Mpa. The steam consumption is 2000 kg/hr and mechanical efficiency is 85% if indicated mean effective pressure is 600 Kpa, determine brake thermal efficiency.

15.25%

A heat exchanger was installed purposely to cool 0.50 kg of gas per second. Molecular weight is 32 and k = 32. The gas is cooled from 150 degC to 80 DegC. Water is available at the rate of 0.30 kg/s and at a temperature of 5 degC. Calculate the exit temperature of the water in degC.

44.86

Steam expands adiabatically in a turbine from 200 Kpa, 400 DegC to 400 Kpa, 250 DegC. What is the effectiveness of the process in percent assuming an atmospheric pressure of 18 DegC. Neglect changes in kinetic and potential energy.

79.46

A steam condenser receives 10 kg/s of steam with an enthalpy of 2770 kj/kg. steam condenses into a liquid and leaves with an enthalpy of 160 kj/kg. cooling water passes through the condenser with temperature increases from 13 DegC to 24 DegC. Calculate the water flow rate in Kg/s.

567

In an open feedwater heater for a steam plant, saturated steam at 7 bar is mixed sub- cooled liquid at 7 bar and 25 degC. Just enough steam is supplied to ensure that the mixed steam leaving the heater will be saturated liquid at 7 Bar when heater efficiency is 95%. Calculate the mass flow rate of sub-cooled liquid if steam flow rate is 0.865 kg/s.

2.869 kg/s

A superheat steam Rankine cycle has turbine inlet conditions of 17.5 MPa and 530 degC expands in a turbine to 0.007 Mpa. The Turbine and pump polytrophic efficiencies are 0.85 and 0.75 respectively, pressure losses between pump and turbine inlet are 1.5 Mpa. What should be the pump work in Kj/kg?

25.32

A certain gas at 101.325 Kpa and 10 degC whose volume is 2.83 m^3 are compressed into a storage vessel of 0.31m^3 capacity. Before admission, the storage vessel contained the gas at a pressure and temperature of 137.8 Kpa and 26 degC; after admission the pressure has increased to 1171.8 Kpa. What should be the final temperature of the gas in the vessel in kelvin?.

314.2

An ideal gas at 0.80 atmosphere and 87degC occupies 0.450 liter. How many moles are there is the sample? (R=0.0821 liter- atm/mole-K)

0.0122 mole

The lower half of a 10 m high cylindrical container is filled with water and upper half with oil that has SG= 0.85. determine the pressure difference between the top and bottom of the cylinder.

90.74 Kpa

The barometer of a mountain hiker reads 930mbars at the beginning of a hiking reads 780 mbar at the end. Neglecting the effect of altitude on local gravitational acceleration, determine the vertical distance climbed. Assume g = 9.7 m/s^2.

1289.00 m

Determine the atmospheric pressure at a location where barometric reading is 740mm Hg and gravitational acceleration is g = 9.7m/s^2. Assume the temperature of mercury to be 10 deg.C at which the density is 13,570 kg/m^3.

97.41 kpa

Two kilogram of air in a rigid tank changes its temperature from 32degC to 150degC. Find the work done during the process.

Air is compressed adiabatically from 30degC to 100degC. If mass of air being compressed is 5kg, Find the change of entropy?.

A dual cycle has an initial temperature of 30C. the compression ratio is 6 and the heat addition at constant volume process is 600kj/kg. if cut off ratio is 2.5, find the maximum temperature of the cycle.

3365.50 deg C

A diesel cycle has a cut off ratio of 2.5 and expansion ratio of 4. Find the clearance of cycle.

11.11%

A volumetric analysis of a gas mixture is as follows: CO2 : 12% O2 : 4% N2 : 80% CO4 : 4% What is the percentage of CO2 on a mass basis?

17.55%

A gaseous fuel mixture has a molal analysis: H2 = 14% O2 = 0.6% CH4 = 3% CO2 = 4.5% CO = 27% N2 =50.9% Determine the air-fuel ratio for complete combustion on molal basis.

1.233

Carnot cycle a,b,c are connected in series so that the heat rejected from a will be the heat added to B an heat rejected from b will be added to c. each cycle operates between 30degC and 400degC. If heat added to A is 1000kw, find the work output of C.

111.4 kw

A 3 stages air compressor compresses air from 100kpa to 700kpa. Find the intercooler pressure between 2nd and 3rd stage

365.88 kpa

A 10—stages air compressor compresses air from 100kpa to 800kpa. Find the intercooler pressure between the first and second stage.

123.11 kpa

A three stages air compressor compresses air from 100kpa to 1000kpa. Find the intercooler pressure between the first and second stage.

215.44kpa

Determine the theoretical weight of Nitrogen in lb/lb of coal

7.526

machine design 2

ユーザ名非公開 · 5問 · 2年前

machine design 2