Looking Amity University Noida 4th Semester Previous Years Question Papers ? Available here is B.Tech MAE, HEAT and MASS TRANSFER 2010 Question Paper. Go through the contents provided below to get a copy of HEAT and MASS TRANSFER question paper.
Amity University Noida
QP Code: BTM-402
B.TECH (M.A.E.)
FOURTH SEMESTER
Exam Type: END TERM EXAMINATION
Exam Year : APRIL 2010
HEAT and MASS TRANSFER
TIME:3 Hrs [Maximum marks 70]
SECTION -A [ Marks 30]
Attempt any 5 questions
Each question carry 6 marks.
1. Derive the Fourier three dimensional conduction equation in cylindrical co-ordinates.
2. (a) A 160 mm diameter pipe carrying saturated steam is covered by a layer of some material of thickness 40 mm & K=0.8 W/m 'C. Later an extra layer of same material having thickness 10 mm & K=1.2 W/m 'C.If the surrounding temprature remains constant and heat transfer co-efficient is 10W/m.m 'C,determine the percentage change in the rate of heat loss due to the extra layer.
(b) What do you mean by thermal diffusivity? What is its physical significance.
3. (a)An electrical conductor of 10mm diameter and having 2mm thick insulator (K=0.18 W/m-K) covering is located in air at 25'C having convection heat co-efficient of 8 W/m.m -K.Ifthe base conductor has specific resistance of 72 u.omega-cm and its surface temperature is 80'c determine,
(1) Current capacity of conductor.
(2) Critical thickness of insulation.
(3) Maximum current carrying capacity.
(b) What do you mean by the term log mean area of a cylinder?
4.(a) Air flows over a plate 0.5m long and 0.6m wide with a velocity of 4m/s.The velocity profile is
{u/U} = Sin{(pie/2)(y/delta)}
{delta=thickness of boundary layer}
If density=1.24 Kg/m-cube and kinematic viccousity = 0.15 * 10{power -4} m-square /s.
calculate:
(1) Boundary layer thickness at the end of the plate.
(2) Shear stress at 250 mm from the leading edge.
(3) Drag force on one side of the plate.
(b) Define Prandtl no. and nusselts no.
5. (a) Define the following terms:
(1) Total emissive power
(2) Monochromtic emissive power
(3) Emissivity
(4) Intensity of radiation
(b) How does a gray body differ from a black body?
6. (a) What do you mean by effectiveness and efficiency of an heat exchanger?
(b) What do you mean by fouling in a heat exchanger?
SECTION-B
Attempt any two questions.
Each question carry 10 marks.
7. (a) One end of a long rod 35mm in diameter is inserted in a furnace with the other end projection in the outside air.After the steady state is reached the temperature of the rod is measured at two points 180 mm apart and found to be 140'C and 180'C.The atomospheric air temperature is 25'C.If the heat temperature co-efficient is 65W/M-square'C, calculate the thermal conductivity of the rod.
(b) Derive the two special case of heat conduction through a rectangular fin when
(1) The tip of the fin is insulated.
(2) The fin is infinitely long.
8 (a) Explain the formation of hydrodynamic boundary layer and thermal boundary layer due to natural convetion.
(b) State the advantages and limits of dimensional analysis.
9. The flow rates of hot water and cold water streams running through a parallel flow heat exchanger are .2kg/s and .5kg/s. The inlet temparature on the cold and heat sides are 75'C and 20'C respectively. The inlet temperature of hot and cold sides are 75'C and 20'C respectively.The exit ttemperatureof hot water is 45'C.If the individualheat transfer co-efficients om both sides is 650W/m-square 'C,calculate the area of heat exchanger.
SECTION- C
(Compulsory)
10.(a)The radiation shape factor of the circular surface of a thin holow cylinder of 10cm diameter and 10cm diameter and
10cm length is 0.1716.What is the shape factor of the curved surface of cylinder with respsct to itself? [marks 6]
(b) What is the radiation shield? [marks 2]
(c) Derive the energy equation for thermal boundary layer in cartesian co-ordinates. [marks 8]
(d) Atmospheric air at 20'C is flowing parallel to a flat plate at a velocity of 2.8m/s.Assuming cubic velocity profile and using exact BLAUSSIUS solution,estimate the boundary layer thickness and the local co-efficient of drag at x=1.2m from the leading edge of plate.Also find the deviation of the approximate solutionfrom the exact solution.Take the knematic viscousity at 20'C=1.54*10{power-6} m-square/s. [marks 4]
Amity University Noida
QP Code: BTM-402
B.TECH (M.A.E.)
FOURTH SEMESTER
Exam Type: END TERM EXAMINATION
Exam Year : APRIL 2010
HEAT and MASS TRANSFER
TIME:3 Hrs [Maximum marks 70]
SECTION -A [ Marks 30]
Attempt any 5 questions
Each question carry 6 marks.
1. Derive the Fourier three dimensional conduction equation in cylindrical co-ordinates.
2. (a) A 160 mm diameter pipe carrying saturated steam is covered by a layer of some material of thickness 40 mm & K=0.8 W/m 'C. Later an extra layer of same material having thickness 10 mm & K=1.2 W/m 'C.If the surrounding temprature remains constant and heat transfer co-efficient is 10W/m.m 'C,determine the percentage change in the rate of heat loss due to the extra layer.
(b) What do you mean by thermal diffusivity? What is its physical significance.
3. (a)An electrical conductor of 10mm diameter and having 2mm thick insulator (K=0.18 W/m-K) covering is located in air at 25'C having convection heat co-efficient of 8 W/m.m -K.Ifthe base conductor has specific resistance of 72 u.omega-cm and its surface temperature is 80'c determine,
(1) Current capacity of conductor.
(2) Critical thickness of insulation.
(3) Maximum current carrying capacity.
(b) What do you mean by the term log mean area of a cylinder?
4.(a) Air flows over a plate 0.5m long and 0.6m wide with a velocity of 4m/s.The velocity profile is
{u/U} = Sin{(pie/2)(y/delta)}
{delta=thickness of boundary layer}
If density=1.24 Kg/m-cube and kinematic viccousity = 0.15 * 10{power -4} m-square /s.
calculate:
(1) Boundary layer thickness at the end of the plate.
(2) Shear stress at 250 mm from the leading edge.
(3) Drag force on one side of the plate.
(b) Define Prandtl no. and nusselts no.
5. (a) Define the following terms:
(1) Total emissive power
(2) Monochromtic emissive power
(3) Emissivity
(4) Intensity of radiation
(b) How does a gray body differ from a black body?
6. (a) What do you mean by effectiveness and efficiency of an heat exchanger?
(b) What do you mean by fouling in a heat exchanger?
SECTION-B
Attempt any two questions.
Each question carry 10 marks.
7. (a) One end of a long rod 35mm in diameter is inserted in a furnace with the other end projection in the outside air.After the steady state is reached the temperature of the rod is measured at two points 180 mm apart and found to be 140'C and 180'C.The atomospheric air temperature is 25'C.If the heat temperature co-efficient is 65W/M-square'C, calculate the thermal conductivity of the rod.
(b) Derive the two special case of heat conduction through a rectangular fin when
(1) The tip of the fin is insulated.
(2) The fin is infinitely long.
8 (a) Explain the formation of hydrodynamic boundary layer and thermal boundary layer due to natural convetion.
(b) State the advantages and limits of dimensional analysis.
9. The flow rates of hot water and cold water streams running through a parallel flow heat exchanger are .2kg/s and .5kg/s. The inlet temparature on the cold and heat sides are 75'C and 20'C respectively. The inlet temperature of hot and cold sides are 75'C and 20'C respectively.The exit ttemperatureof hot water is 45'C.If the individualheat transfer co-efficients om both sides is 650W/m-square 'C,calculate the area of heat exchanger.
SECTION- C
(Compulsory)
10.(a)The radiation shape factor of the circular surface of a thin holow cylinder of 10cm diameter and 10cm diameter and
10cm length is 0.1716.What is the shape factor of the curved surface of cylinder with respsct to itself? [marks 6]
(b) What is the radiation shield? [marks 2]
(c) Derive the energy equation for thermal boundary layer in cartesian co-ordinates. [marks 8]
(d) Atmospheric air at 20'C is flowing parallel to a flat plate at a velocity of 2.8m/s.Assuming cubic velocity profile and using exact BLAUSSIUS solution,estimate the boundary layer thickness and the local co-efficient of drag at x=1.2m from the leading edge of plate.Also find the deviation of the approximate solutionfrom the exact solution.Take the knematic viscousity at 20'C=1.54*10{power-6} m-square/s. [marks 4]
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