(3) Determine total energy transfer amount() (10 pts) (4) Determine if the Lumped capacitance model can be applied (10 pts)
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Problem 1 (35 pts) The gold sphere, which is 20 mm in diameter, is located at 75°C before it is i...
The heat transfer coefficient for hydrogen flowing over a sphere is to be determined by observing...
The heat transfer coefficient for hydrogen flowing over a sphere is to be determined by observing the temperature–time history of a sphere fabricated from pure copper. The sphere, which is 20.0 mm in diameter, is at 70°C before it is inserted into the gas stream having a temperature of 27°C. A thermocouple on the outer surface of the sphere indicates 50°C 97 s after the sphere is inserted into the hydrogen. Find a) What is the value of the specific...
The heat transfer coefficient for hydrogen flowing over a sphere is to be determined by observing...
The heat transfer coefficient for hydrogen flowing over a sphere is to be determined by observing the temperature–time history of a sphere fabricated from pure copper. The sphere, which is 20.0 mm in diameter, is at 90°C before it is inserted into the gas stream having a temperature of 27°C. A thermocouple on the outer surface of the sphere indicates 40°C 97 s after the sphere is inserted into the hydrogen. Step 1 What is the value of the specific...
7. (20 pts) A sphere with 30 mm in diameter initially at 800 K is quenched...
7. (20 pts) A sphere with 30 mm in diameter initially at 800 K is quenched in a large bath having a constant temperature of 320 K with a convection heat transfer of 75 W/m2.K. The thermophysical properties of the sphere material are: p=400 kg/mº, c=1600 J/kg-K, and k=1.7 W/mK. (Use characteristic length Lc=VIA to determine applicability of lumped method; Use radius of the sphere for one term approximation) a) Calculate the time required for the surface of the sphere...
PROBLEM 4 (20 pts) Water at 25 °C is used to cool oil from 120 °C...
PROBLEM 4 (20 pts) Water at 25 °C is used to cool oil from 120 °C to 80 °C. Oil flows at a rate of 1 kg/s in a tube of inside diameter 1.6 cm and outside diameter 1.9 cm. The tube makes 18 passes in a shell. Water flows through the shell at a rate of 1.5 kg/s. The water side heat transfer coefficient is 12,000 W/m2°C. Oil properties at 100 °C are: Cp = 2219J/(kg.), k = 0.137...
A long wire with circular cross section and diameter D = 1 mm is submerged in an oil bath with temperature To 20。C. The wire is initially at temperature T = 20。C, the same temperature as the oil. A...
A long wire with circular cross section and diameter D = 1 mm is submerged in an oil bath with temperature To 20。C. The wire is initially at temperature T = 20。C, the same temperature as the oil. A current is passed through the wire, resulting in a volumetric heat generation of q - 1.5 x 108 W/m3. The convection coefficient is h - 500 W/m2 - K, and the properties of the wire are ρ-8000 kg/m3, Cp-500 J/kg-K, and...
Problem 3 (20 points) A cross-flow heat exchanger consists of a bundle of 32 tubes in a long duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters...
Problem 3 (20 points) A cross-flow heat exchanger consists of a bundle of 32 tubes in a long duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters of 10.2mm and 12.5mm and has to be cooled to 136°C. The tubes are made of steel of thermal conductivity k-40 W/m.K. Air at 10°c enters the exchanger (unfinned) with a volumetric flow rate of 1.0 m3/s. The convective heat transfer coefficient...
I need your help solving this thermodynamics problem please: Question Completion Status: QUESTION 1 20 points...
I
need your help solving this thermodynamics problem please:
Question Completion Status: QUESTION 1 20 points Save Ans The heat-pump system shown is designed to provide water-heating and space-cooling. The system includes a heat exchanger to subcool the R134a refrigerant at the outlet of the water heater while heating the refrigerant at the outlet of the evaporator. Given the following data, determine the enthalpy at each station, 1 through 6, using the R134a property tables (click here). Type your answers...
7. (20 pts) A sphere with 30 mm in diameter initially at 800 K is quenched in a large bath having a constant temperature of 320 K with a convection heat transfer of 75 W/m2.K. The thermophysical properties of the sphere material are: p=400 kg/mº, c=1600 J/kg-K, and k=1.7 W/mK. (Use characteristic length Lc=VIA to determine applicability of lumped method; Use radius of the sphere for one term approximation) a) Calculate the time required for the surface of the sphere...
PROBLEM 4 (20 pts) Water at 25 °C is used to cool oil from 120 °C to 80 °C. Oil flows at a rate of 1 kg/s in a tube of inside diameter 1.6 cm and outside diameter 1.9 cm. The tube makes 18 passes in a shell. Water flows through the shell at a rate of 1.5 kg/s. The water side heat transfer coefficient is 12,000 W/m2°C. Oil properties at 100 °C are: Cp = 2219J/(kg.), k = 0.137...
A long wire with circular cross section and diameter D = 1 mm is submerged in an oil bath with temperature To 20。C. The wire is initially at temperature T = 20。C, the same temperature as the oil. A current is passed through the wire, resulting in a volumetric heat generation of q - 1.5 x 108 W/m3. The convection coefficient is h - 500 W/m2 - K, and the properties of the wire are ρ-8000 kg/m3, Cp-500 J/kg-K, and...
Problem 3 (20 points) A cross-flow heat exchanger consists of a bundle of 32 tubes in a long duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters of 10.2mm and 12.5mm and has to be cooled to 136°C. The tubes are made of steel of thermal conductivity k-40 W/m.K. Air at 10°c enters the exchanger (unfinned) with a volumetric flow rate of 1.0 m3/s. The convective heat transfer coefficient...
I
need your help solving this thermodynamics problem please:
Question Completion Status: QUESTION 1 20 points Save Ans The heat-pump system shown is designed to provide water-heating and space-cooling. The system includes a heat exchanger to subcool the R134a refrigerant at the outlet of the water heater while heating the refrigerant at the outlet of the evaporator. Given the following data, determine the enthalpy at each station, 1 through 6, using the R134a property tables (click here). Type your answers...
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