Filter Element Robustness Strategy for Mud Ingestion

Air filter elements have been around since the dawn of automotive development. The function of an air induction system and the filter element in particular is to remove particulates such as dust, soot, and relatively minor contaminants from the air flow. This protects the engine, turbocharger, and other components from wear. However, sometimes severe duty cycles may cause large amounts of dust, mud, and water to enter the air induction system (AIS). This can cause filter degradation and even rupture or deformation, leading to highly increased engine and turbocharger wear. One example of this extreme loading is the tar sands region of Alberta, Canada, where trucks can accumulate over 1000 pounds of mud on a vehicle during normal usage over a few weeks’ time. Significant amounts of this mud also get ingested into the AIS.

This study attempts to analyze different aspects of filter design to increase robustness to severe usage, particularly mud. Different aspects studied are filter element structure, filter element media, inlet location, and inlet blocking. Traditional ISO 5011 tests would not replicate the mud aspect that was sometimes seen in the field. To get a repeatable laboratory measurement, the authors developed a new mud cycle for testing that alternates a water spray and normal ISO 5011dust injection to accumulate mud on filter elements until rupture or deformation, causing a bypass. This test showed similar results of deformation as was seen in Alberta. Using this testing process, various filter elements with varying design attributes such as media type, filter element sizes etc. are tested and compared. This study compares different filter elements and comes up with a relation between the different filter design attributes and mud testing performance. Knowing the design factors that play a significant role in affecting the performance would help to design better, mud enduring filter elements in the future. Concurrently, virtual simulations are performed on a couple of filter elements with significantly different design and inlet area to help compare the flow dynamics of mud and water particles. Flow simulation studies also validate the obtained testing results and aid in providing more design recommendations.