Gear box Sloshing simulation

Objective:- In this Challenege we have to perform Gearbox Sloshing Effect simulation. HEre we have to work on four diffrenet cases. There are two geomrtry provided by the skill lync.Having different clearance maintained between the gears of an Gerabox. So we have two geometry and also we have to do two seprate analysis for each of those gearbox geometry by changing the fluids in the lubricating region of an Gearbox.

Setup and preprocessing settings :-

The preprocessing settings are similar for each of the cases there is minute difference in cases like,center of volume co-ordinates and Defining the fluid regions,Also there is a case where i used water and air ,And the cases where oil and air.

Case1- The geometry with the closed clerance

Fluids used (Air and Water)

Case 2.-The geometry with closed clerance

Fluid used ( Air And oil)

Case 3.- The geometry with increased clerance

Fluids used (Air and Water)

Case4- The geometry with increased clerance

Fluid used ( Air And oil)

The geometry with closed clerance having center of volume base on co-ordinate The geometry with increased clerance having center of volume base on co-ordinate

(0,0,0) m =For left gear ; (-0.115,0,0)m =For Right gear (-0.0684485,0,0) m =For left gear ; (0.0485515,0,0)m =For Right gear These valuse are used for setting up dynamic mesh for left and right gear

Fluid region co-ordinates for closed clearence geometry Fluid region co-ordinates for closed clearence geometry xmin=-0.05612m xmax=0.17112 m xmin=-0.117m xmax=0.1169534m ymin=-0.0675 m ymax=-0.0375m ymin=-0.0356371 m ymax=-0.099m Above shown valuse are used for defining the level of lubricating filled inside the gearbox.

Procedure for how i set-up all this settings in the Fluent.\\

In this challenge we have to open ansys by Visual c++ compiler, By coping the link file of workbench in it. After sucessfully opening of ansys ,Fluent was dragged in the Working window and the space claim was opened up,Here in the space claim Step file for gearbox was dragged and imported then the voule eas extracted by selecting the edged at the sides of housing. After the Volume extraction the geometry was split up from the origin at Front plane. And the face was selected at the front of cut section.and it was open as a new design . here we only required the 2d surface of gear and the fluid region to simulate the air and other fluid mixture while gears are rotating.

In this way the surface was extracted for the simulation or for further processing.. After this the model is impoted in the meshing module.For mesh creation and for named selection.

mesh size=30mm And the face sizing is automatic with trangles generation method.

AFter mesh creation named selction was created to define the edges for dynamic meshing .

Fluent preprocessing settings.

Set-up was open-up which again open a Fluent here As the mesh is ready to display .

1. Basic Formulation setting are defined ,The analysis is transient and pressure based,Also the gravity is enabled in the negative Y-direction.As in this analysis two fluids are interacting each other so we also had defined the multiphase formulation setting as Volume of fluid method . Also the viscous model wad enabled with E-eplsilon formulation Along with the standard setting of Realizable model and Enhances wall teratment.

After doing this the (udf)used defined function was defined tab Add udf file And The udf contain the information of angular velocity for the gear and the rotation provided to left and right gear and the contour direction ,

After those Dynamic mesh is set with the co-ordinating position of Left and roght gear at the starting of report ,The co-ordinates are provided Already for both the gear interface conditions.

The geometry with closed clerance having center of volume base on co-ordinate The geometry with increased clerance having center of volume base on co-ordinate

(0,0,0) m =For left gear ; (-0.115,0,0)m =For Right gear (-0.0684485,0,0) m =For left gear ; (0.0485515,0,0)m =For Right gear These valuse are used for setting up dynamic mesh for left and right gear

After this setting Adaptive region was created arbitorily ,This will define the fluid region inside the gear box ,Similarly for tjis condition the co-ordinates are specified at the starting of report For both the intefaces model.

Fluid region co-ordinates for closed clearence geometry Fluid region co-ordinates for closed clearence geometry xmin=-0.05612m xmax=0.17112 m xmin=-0.117m xmax=0.1169534m ymin=-0.0675 m ymax=-0.0375m ymin=-0.0356371 m ymax=-0.099m Above shown valuse are used for defining the level of lubricating filled inside the gearbox.

Now the next i had done HJybrid initialization And Patched the fluid region So that the liquid will remain present only in the Adaptive region which was defined by co-ordinates .

Then defined a new contour to check the fluid regions are properly setup properly or not.Solution animation was created for each cases .

Here to achive desired solution meshing conditions are modified to avoid the negative cell volume detection during analysis .

Stetings for each simulations.

During solving it tooks me to solve 6 hour but still i was not able to achieved end time step so afted 10 % i stopped the simulation and recorded the animation for all the respective cases .

all the animation files are attached by google drive.

all animation =https://drive.google.com/open?id=1hr8TmvfpRvxRfLTpGd8hYrAxnyZY2SQ8

Case 1:-

The animation is pretty decent all the gears are covering with fluid also the air in the lower bottom portion are extracted due to pressure difference. Her the fluid is Air and water is used for lubricating purpose.

Case 2:-

here the closed clerance model was used also the fluid are air and oil.,During the perfoemance of this simulation i used water from fluent database and edited the property of water and replced it with the oil properties.so It will behave as an oil in the fluid region.

case3:-

Here the model used was with increased clearence and fluids are Air and water.

Case 4:-

In this case model used was increased clearence with fluids interaction of air and oil.

In this way i performed all the case simulations by refering the videos tutorial, The main thing to learn in the case 3,4 is defining the co-ordinates to setup the movement of gears in the dymanic mesh pannel, also fluid region was defined arbitorily,by sketching the plots on the geometry of increased clerance gearbox on Space claim.Also in the case where i used oil having smooth flow patten during animation review, because the oil viscocity is higher so the molecules of oil having tendency to stick with the surface of gears and provide frictionalless movement. And when the flow pattern with water was analysed it seems that the fluid is not entirely staying on the surface of gear instead it dispersed over the entire region creating different low pressure region.

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