cfd analysis of ceiling fan by lucas tvs limited · cfd analysis of ceiling fan by lucas tvs...
TRANSCRIPT
Duraisamy P
Sr. Development Engineer
CFD analysis of ceiling fan
by
Lucas TVS Limited
22nd July 2016
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Company profile
Established 1962, JV - Lucas UK and TVS
Wholly owned since 2001
7 plants in India
Main plant in Chennai - 2600 employees
Complete Product development capability 75% of revenue from products
developed In-house
TS16949 and OHSAS 18001 certified company
Deming grand prize in 2012 for excellence in applying the principles of
TQM
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Products
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CFD analysis of ceiling fan
Objective of case study
To perform flow simulation of ceiling fan.
Analyse the fluid flow and predicted results.
Establish correlation with experimental data.
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Geometry Nomenclature and Spec
Top canopy
Downrod
Blade
Blade flange
Specifications
Fan sweep 1200 mm
No of blade 3
Blade thickness 1.2 mm
Fan speed 350 RPM
Range of speed 280-350 RPM
Rotation CCW from floor
Evaluate flow rate as per IS 374 -1979 specification.
Determine mechanical input power
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IS 374-1979 spec - test chamber
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Virtual flow chamber
4.2
5 m
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Virtual chamber surfaces
Floor
Bottom opening
Outer wall
Roof
Top opening
Test chamber wall
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Diaphragm - Top opening and Rot domain
Enlarged View
Top opening recommanded diameter is 1.1 to 1.2 times of fan sweep diameter.
Fan - Rotating domain
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Surface and Volume mesh
Mesh - Cut section view
Surface Mesh
Boundary layer mesh created over blade surfaces. Conical mesh created to capture flow under fan region.
Surface mesh created in HM.Surface mesh can constrcut volume.
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Input details and Boundary conditions
Material properties: Input speed:
Density of air 1.2 kg/m3
Viscosity of air 1.8 e-5 Ns/m2
Boundary Condition:
• Wall BC to all the outer walls.
• No BC to rot domain surfaces.
• Pressure point is created in domain
to initiate simulation.
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Velocity measurement points
Test chamber wall
Probe points at four semi diagonalsbegins at 40 mm from centre and 80 mm incremental in all diagonals.
The measurement plane located 1.5 m below plane of fan blades.
Mesurement points are shown below which are used to read value of velocity.
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Solution convergence - AcuProbe
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Stream lines
Air entering into top opening and fan moves air with higher velocity.
Air comes out through bottom opening from chamber and circulated.
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Velocity contour
X Z plane - velocity contour
Z axis component velocity contour shown below
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Velocity contour cont..
X Y plane - velocity contour
0.01 m 0.5 m
1 m 1.5 m
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CFD results
Steady state analysis performed.Velocity evaluated at discrete points of four semi diagonals.Geometry position - A blade oriented to Y axis.
0 Deg
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CFD results - Three different initial positions
Accumulated air flow rate : 242 CMMTorque required to develop flow : 0.75 Nm @ 350 rpm
0 Deg30 Deg
60 Deg
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Test results
Velocity profile along four semi - diagonals are shown below.
Accumulated air flow rate : 231 CMMTorque : 0.74 Nm @ 350 rpm
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Comparision
S No Parameters Test results CFD results Remarks
1Flow domain
size
IS 374 - 1979
followed
IS 374 - 1979
followed
Thickness of chamber neglected
2Speed
RPM350 350
Input for simulation
3Flow rate
CMM231 242 5% variation
4 Torque
Nm0.74 0.75 2% variation
5Power
W27 W 27.5 2% variation
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AcuSolve could predict the flow parameters for given input speed of ceiling fan
by
1. Flow rate >95 % accuracy.
2. Torque >95% accuracy
Conclusion
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Benefits summary
Flow simulation method has been established to evaluate airflow rate and mechanical input power of fan as per IS 374 - 1979 specification.
This methodology proposed to optimize fan blade design in order to improve efficiency.
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I would like to acknowlegde
1. The excellent support provided - M/s DesignTech sys Ltd
2. Lucas TVS providing the permission to present fan simulation work in ATC 2016
Acknowledgements/Credits