Week 3 Challenge : CFD meshing on Turbocharger

A turbocharger is a turbine-driven force induction device that boosts the efficiency and power output of internal combustion engines by forcing additional compressed air into the combustion chamber.

This hot air induction appears to work because the compressor can force more air and, by extension, more fuel into the combustion chamber than normal atmospheric pressure.

The difference between a turbocharger and a conventional supercharger is that a turbocharger is powered by a turbine driven by an engine’s exhaust gas. Whereas, a supercharger is mechanically driven by the engine crankshaft, often connected with a belt. However, turbochargers are more efficient but less responsive. The term Twin-charger is referred to an engine with a turbocharger and a supercharger.

The primary function of a turbocharger is to increase the working efficiency of an automobile engine. Below are reasons why Turbo will always exist despite a few of its limitations.

• Extra oomph is provided without increasing the engine capacity.
• Make the engine run faster without an increase of fuel burning rate.
• Make use of carbon II oxide (exhaust gas) instead of causing pollution.

As we are performing internal flow analysis, the thickness of the geometry becomes redundant, so to remove those thicknesses, we are performing COONS release operations, which will project those thicknesses as free surfaces.

After fixing all the geometrical errors, we finally got our water-tight geometry.

Now we need to check the geometry and intersection errors present in the geometry.

Checks -> Checks Manager -> Geometry Checks

Now, we can see there are triple coons present on the shaft

Here, we need to decide the future of triple coons we need to keep it or not...If we want to define it as a multiple volume triple coons, similarly if we want to define it as a single volume triple coons should be eliminated.

After fixing all the geometrical and intersection errors, we finally achieved our clean geometry.

Now after geometrical cleanup we need to assign PIDs to different components of the given geometry,so here is

Blade Stage-1

Blade Stage-2

Compressor Casing

Impeller

Shaft

Turbine Casing

Turbine Inlet

Now we need to move to the Mesh Deck and start our Meshing Process.

Here,First of all we need to perform Surface Meshing Operation.

Surface Meshing - A surface mesh consists of a set of polygonal faces, often triangles, that, taken together, form a surface covering of the object. The advantage of a surface mesh is that it is fast to generate and works very well for visualization. It uses two-dimensional elements, typically triangles or quads, to approximate the outer surface of a 3D body. Surface meshes are used in manufacturing or rendering applications and CAE simulation.

Batch Mesh Manager -> New -> Meshing Scienario -> Edit -> Contents -> Select all the available contents

We have configured our Batch Mesh Manager Meshing Configuration and Quality Criteria and now we can proceed further.

After that, we need to define Layers Scienario

Batch Mesh Manager -> New -> Layers Scienario -> Edit -> Contents

We have assigned layers scenario to capture the boundary layer near the wall area, i.e., casing and inlet.

We can observe our seven boundary layers in Cut Section View Plane.

We can observe here that there are lots of off elements which needs to be fix..

We can use Reconstruct Solids which would help us to imrove such off-elements..After hitting it a few times,it helped us decrease our off-elements significantly.

Now, we tried to fix off-elements using Improve -> Fix Quality -> Visible which helped us eliminate our off elements successfully.

Now we can move to Volumetric Meshing

While trying to generate volumetric meshing, there was an intersection error that popped up.Which got fixed by erasing and re-generating CFD Mesh in that specific region and some off-elements was fixed by re-shape the geometry in that specific region.

Now after fixing few Unmeshed Elements Error..Finally fully Meshed Geometry is achieved.

Results

File Link - https://drive.google.com/file/d/16Pu6JMv_SyVM4O8mUO3R33lXgoy3vzOw/view?usp=share_link