Louise Andersson & Linus Hermansson presenterar sitt examensarbete

Program: MSc Product Development
Examinator: Johan Malmqvist, IMS
Opponenter: Matilda Blomgren & Stefán Gunnarsson

Abstract

This study focuses on designing an air filter box for REX (range extender) engine applications in medium/heavy-duty trucks. The aim is to meet industry requirements by designing an air filter box and duct bellow that fulfill the necessary criteria. The research questions addressed include identifying current designs and filters used in the automotive industry and establishing technical requirements. Along with exploring design possibilities, and evaluating how the new designs can meet and exceed expectations. By comparing existing designs, establishing requirements, and exploring design possibilities, this study provides a design for an air filter box and duct bellow that meet the requirements and can be produced. It also provides Aurobay with a foundation for future air filter box designs.

The study includes a literature review and comparative benchmarking of existing air filter system designs in the automotive industry. Technical requirements are established through interviews, considering factors such as air flow, air quality, pressure drop, leakage, durability, and space constraints. CAD modeling and CFD simulations are then conducted to evaluate design parameters' impact. The results highlight the significance of factors like inlet placement, inlet angle, guides, distance between the inner wall and filter, filter thickness, radius on the outlet, and inlet design on the air filter box's performance.

Two significant findings emerge from the study. The radius on the inlet and outlet plays a crucial role in determining UI (uniformity index) over the outlet and air filter. Additionally, placing the bellows on the duct at a greater distance from the box improves uniformity over the MAF (mass flow sensor).

The recommended final concept is a rectangular air filter box with a flat-shaped filter. It incorporates a short duct bellow for cost optimization and the inlet is positioned near the top of the engine to create a shorter path for a dirty side duct. The air filter box is divided into two parts for easy placement and replacement of the air filter and is securely fastened using screws. Hexagonal pattern ribs on the top lid and outer surface of the bottom part enhance structural integrity, while rounded corners and edges prioritize safety. The recommended concept fulfills the requirements and serves as a valuable guide for Aurobay's future air filter box designs.