An interior sound quality is one of the major performance attribute, as consumer envisage this as class and luxury of the vehicle. With increasing demand of quietness inside the cabin, car manufactures started focusing on noise refinement and source separation. This demand enforces hydraulic power steering pump to reduce noise like Moan and Whine, especially in silent gasoline engine.
To meet these requirements, extensive testing and in-depth analysis of noise data is performed. Structured process is established to isolate noises and feasible solutions are provided considering following analysis.
- a)
Overall airborne noise measurement at driver ear level (DEL) inside the cabin using vehicle interior microphone.
- b)
Airborne and Pressure pulsation test by sweeping pump speed and pressure at test bench.
- c)
Waterfall analysis of pump at hemi anechoic chamber for order tracking and noise determination.
The work presented in this study involves an experimental approach to characterise the noise & reduce the same by order analysis and attenuate the parts at dominant frequency.
All significant process variable & factors are identified which affect the quality characteristic of noise. Co-relation of vehicle in-cab noise to component level and vice versa is established. Subjective assessment is followed for improvement of same.
The approach and methodology towards arriving to the cost effective solution is to reduce the source of noise, attenuate high pressure (HP) line and Pump mounting brackets at dominant frequency for Moan & Whine noise respectively.