Flow HT208 People associated with the expt. Instructor Prof. - - PowerPoint PPT Presentation

Heat Transfer in Laminar Flow

HT208

People associated with the expt.

• Instructor
• Prof. Jayesh Bellare
• Teaching Assistants
• Satpute Kushal Dadasaheb
• Sudip Kumar Das
• Praveen Nayak
• Laboratory Staff Member
• Mr. S. V. Deshpande

Objective

For laminar flow heat transfer

• Determination of the overall heat transfer

coefficient using logarithmic mean temperature difference

• Calculation for the individual film heat transfer

coefficient

Principle

Background Theory

With respect to the inside area Sieder-Tate equation

Nu = 1.86 x (Re)1/3(Pr)1/3

h = const. x u1/3 1 𝑉𝑗 1 𝑣1/3

= Constant1 x + Constant2

Set up

Flow regulator Calibrated cylinder Heater Pumps Heat exchanger Rotameter

Experimental Procedure

• 1. Start up circulating pumps for both hot and cold fluid
• 2. Switch on the heater for heating up the hot fluid
• 3. Steady state reached:
• Note hot fluid and cold fluid inlet and outlet temperature
• Measure volumetric flow rate of hot fluid (laminar flow regime)
• 4. Change volumetric flow rate of hot fluid keeping other

parameter unchanged

• 5. Repeate step no. 3

Data collection

• From experiment
• Cold fluid volumetric flow rate (fixed)
• Cold fluid inlet and outlet temperature
• Hot fluid volumetric flow rate (manipulated variable)
• Hot fluid inlet and outlet temperature
• From literature
• Density of cold fluid at 30OC
• Density, viscosity, thermal conductivity and heat capacity of hot

fluid at 65OC

• Supplied
• Dimensions of heat exchanger, tubes

Calculation

Q = V x ρ x Cp x (T1-T2) LMTD = 𝑈1 − 𝑢1 − (𝑈2 − 𝑢2) ln⁡ * 𝑈1 − 𝑢1 /(𝑈2 − 𝑢2)+ U =

𝑅 𝐵Δ𝑈𝑚𝑜

1/U 1/u1/3 Wilson Plot for Laminar flow heat transfer

Safety issue

• Careful during volumetric

flow rate measurement of hot fluid

THANK YOU