The document summarizes optimization of an intake air cleaner through computational fluid dynamics (CFD) and noise, vibration, and harshness (NVH) analysis. The analysis aims to meet pressure and frequency targets. Modifications are made to the geometry to improve airflow and reduce pressure drop based on CFD results. Additional modifications with ribs are made to satisfy the desired frequency range based on NVH analysis. The final modified model meets both the CFD and NVH criteria by achieving the targeted pressure level and frequency.

1. Optimization of Intake Air Cleaner
Srinivas Reddy Gopu G. Naresh Kumar
Deputy Manager Assistant Manager
Hyundai Motor India Engg Pvt Ltd Hyundai Motor India Engg Pvt Ltd
Hyderabad Hyderabad
Abstract
A particulate air filter is a device composed of fibrous materials which removes solid particulates such as dust,
pollen, mold and bacteria from the air. Air filters are used in applications where air quality is important, notably in building
ventilation systems and in engines.
The air intakes of internal combustion engines and compressors tend to use either paper, foam or cotton filters. Oil
bath filters have fallen out of favor. The technology of air intake filters of gas turbines has improved significantly in recent
years, due to improvements in the aerodynamics and fluid-dynamics of the air-compressor part of the Gas Turbines. Purity
and amount of air with the pressure is primary importance in air filter and at the same time stiffness of air cleaner is also
much important in automobile industry. In order to achieve the specified targets we need to perform both CFD and NVH
analysis.
Purpose:
Flow analysis and normal mode analysis was carried out to know the pressure drop in the
Intake air cleaner assembly and to find the frequency values. Optimize the geometry to meet the
desired pressure levels by considering NVH characteristics like frequency and mode shapes.
The main Objectives of this analysis:
• To know the pressure difference between inlet to outlet of the air cleaner assembly.
• To check out the fluid flow volume (by identifying any unnecessary flow volume in the air cleaner).
• Results of this analysis can be used to modify the air cleaner geometry with respect to NVH
analysis.
Fig: Solid model Fig: Fluid model
Introduction
In this paper we are analyzing the intake air cleaner assembly with the help of CFD and NVH
procedure and with this we will know the pressure and frequency. Finally with the help of fluid flow
volume and pressure drop results we will modify the flow region and with frequency results we will
modify the solid region of air cleaner.
Process Methodology:
For all type of approaches, we have same procedure as pre-processing, solving, and
post processing.
Simulation Driven Innovation
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2. The procedure consists of following steps:
1. The finite element modeling of fluid and solid regions was done in Hyper Mesh and it is
exported to AcuSolve and Radioss to perform the flow and stiffness analysis.
2. Set stagnation pressure and mass flux are the inlet and outlet boundary conditions to solve
the flow analysis, and set the frequency range for the normal mode analysis.
3. Hyper View is used to post process the results (i.e fluid flow volume, pressure difference).
Based on these results some modifications have been done to satisfy the CFD and NVH
criteria.
Results & Discussions:
Fig: Base model Fig: Modified model Fig: Final model
Optimization of air cleaner is carried out based on CFD (flow area and pressure drop) and
NVH (Stiffness) analysis. Model validation is carried out with respect to standard design guide lines
such as amount of pressure drop required for particular segment of the car and the amount of
stiffness required avoiding air borne noise. But the results obtained are not attaining specified
values. Due to this, the modifications has been carried out on existing model with the help of design
engineers, to improve fluid flow volume and pressure drop .again Flow analysis is carried out on
modified model from the results it is observed that even though it is good enough in fluid flow region
it is not satisfying Desired frequency range (i.e 277 Hz only).so Further modifications are carried out
by adding ribs on structural side. Final model is which is satisfying both the constraints is shown in
figure.
Conclusion:
The modified model has satisfied in both CFD and NVH criteria. It has achieved the desired
pressure level and frequency.
ACKNOWLEDGEMENTS
We would like to thank our Managing director Mr.Y.S.Roh and Mr. Lee Wong Sang, CAE
–Head of the Department and the PT team for their continued support and for encouraging
throughout the development of this paper.
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