Problem
As the noise requirements become more demanding, the design space of acoustic and vibration isolation for vibrating machines is dramatically reduced. Design goals from other disciplines, such as safety, durability and recyclability, etc., must all be met simultaneously, which increases the complexity of NVH design. At the same time, the demand on lightweight designs is continuously growing, e.g., due to the increasingly stringent European emission regulations. The reduction of weight is generally in conflict to the NVH performance.
Facing the increasing challenges in NVH engineering, the traditional CAE development methods can no longer meet current development demands. Typically, after noise targets, e.g. Sound Pressure Level (SPL) at the driver's ear, are specified, they cannot be cascaded down to individual components. Usually, engineers set component noise targets based on experience - which they lack when entering new design concepts, e.g., for electric vehicles. Without explicit component targets, the corresponding development departments often have difficulties in finding effective measures for NVH improvement. Furthermore, there is no clear standard to verify the success of the component development in the early development stage. Acoustic performance can only be assessed in the late development stage after the mechanical product is fully developed. In order to solve acoustic problems, engineers may have to redesign the entire system, resulting in considerable development time and effort. Finally, a satisfying overall acoustic performance may not be achieved despite of enormous design iterations.
Goal
This project aims to develop a new design process for NVH engineering of complex mechanical systems by breaking down the noise requirements from the system level quantitatively to the component level based on the so-called Solution Space Engineering method (Development Requirement Decomposition). This way, the development of a complex system is decomposed into Component Design problems. The maximum admissible range of each design parameter is computed based on system and component performance evaluation. As long as the design parameter is kept in the derived range, the system requirements are guaranteed to be fulfilled. Quantitative component design goals provide clear guidance for engineers to identify effective NVH measures and conduct component development. In the end, the success of the product development will be verified through the Component Performance Evaluation and the System Performance Evaluation.
The proposed method will offer a systematic procedure to reduce the noise of mechanical systems in presence of system complexity and multidisciplinary requirements. It will significantly accelerate the product development process by reducing design iterations. Its effectiveness will be demonstrated by academic as well as practically-oriented hardware prototype components within the scope of this project.
Approach
WP1: Literature research and test rig preparation
WP2: Research on wiper system
WP3: Selection of demonstrator system and prototype
WP4: Bottom-up system simulation
WP5: Top-down requirement cascading
WP6: Component redesign
WP7: Manufacturing and verification
WP8: Evaluation and documentation
