Gear sloshing effect
GEAR SLOSHING ANALYSIS USING WATER AND OIL
In industrial applications, it is very important to use lubricants in between rotating gears. Lubrication is necessary to reduce coefficient of friction between gear teeth. It also limits the rise of temperature due to sliding and rolling of teeth.
In this case, we are studying how efficiently fluids can reach in between each and every gear teeth when two different fluids, i.e. water and oil are used separately as lubricating fluids and also for 2 different clearance values between the gears.
The CAD model for the gear teeth is shown below:
As we are doing a 2D simulation, the 3D CAD was converted into a 2D surface for the purpose of simulation as shown below:
For meshing, triangular meshing with element size 30mm has been used.
As this is a case of applying motion in the two gears,we have used dynamic meshing using UDF( user defined functions).
Angular velocity `omega=200`rad/sec
Turbulence model used- Realizable k-epsilon model with enhanced wall treatment.
No of time steps- 10000
Size of each time step-0.0001
CASE 1: Distance between center of gears = 0.115 metres
- Lubricating fluid- Water
b. Lubricating fluid- Oil (Density: 871 kg/m^3; Viscosity: 0.04006889 kg/m-s)
CASE 2: Distance between center of gears = 0.117 metres
a.Lubricating fluid- Water
b. Lubricating fluid- Oil (Density: 871 kg/m^3; Viscosity: 0.04006889 kg/m-s)
CONCLUSIONS:
- For the cases of increased clearance(0.117 m), it has been observed that the simulation runs for all the time steps(10000). Whereas, in case of lower clearance between the gaps, negative cell volume gets detected at time step number 9102. This might be due to improper mesh sizing due to dynamic meshing..
- For all the 4 cases, the mixing pattern of lubricants appears pretty similar and not much difference is observed.