System Engineering Approach to NVH Attribute Management for Transport Refrigeration

The transport refrigeration market is in a transformation like what automotive experienced over the last 20 years using a systems engineering approach complemented with complex attribute optimization to manage product development. With a heavy push for electrification due to government regulations, sustainability initiatives, and designing the products to align with the OEMs electrified platforms Noise, Vibration, and Harshness (NVH) must be considered. Understanding the above along with refined customer expectations the NVH attribute has become even more critical to product quality. This paper showcases the acoustic design of an electrified system using a system engineering approach to achieve unit level targets deploying a system engineering V-model philosophy. Unit level requirements were set and flowed down to component level requirements. A 1D acoustic tool was developed leveraging classic physical acoustics theory and legacy product knowledge to target set what was possible for various architecture possibilities and rapidly iterate on design choice implications and complete attribute trade off analysis. Component and unit level testing was utilized to refine model parameters and develop a continuous surface to interpolate and extrapolate system performance. Model verification and validation will be discussed along with final unit qualification to meet requirements. Further work on unit noise optimization using the system model will be covered along with future work for model refinement.