Analytical and Experimental Development to Improve Powertrain System Induced Vehicle NVH Issues

Vehicle Noise, Vibration, and Harshness (NVH) performance has become an important indicator used in the “Customer Satisfaction” category in the automotive industry. Particularly, refinement of powertrain NVH performance in different vehicle operating conditions has had a major contribution to the perception of overall vehicle NVH performance. The powertrain system typically includes the engine and transmission (powerplant), driveline, axle, and induction/exhaust subsystems.

This paper presents three areas of successful development work in resolving vehicle NVH issues using analytical and experimental tools: (1) powertrain bending induced vehicle NVH concerns at high speeds [1]; (2) exhaust modes induced - idle boom, vibrations, and normal vehicle speed moaning noise [2-3]; and (3) driveshaft modes and axle gear mesh force induced axle whine noise [4]. Each development work has resulted in design changes and improved NVH performance in production vehicles.