Vehicle Semi-Anechoic Chamber
At a glance
Millbrookâs semi-anechoic chamber in the UK enables vehicle and transmission NVH tests to be completed in a controlled, repeatable environment with low levels of background noise.
Twin rollers are connected to a 350kW DC machine dynamometer, enabling high power vehicles to be tested using a wide range of drive profiles. The room will accommodate vehicles up to the largest trucks and buses.
- Entrance door size: 4.7m (high) x 3.8m (wide)
- Working area: 19m x 9m x 5m
- Background noise: 40dB (lin)
- Lower cut-off frequency: 70Hz
- Power absorption: 350kW (50 - 130km/h)
- Drive back: 300kW (50 - 130km/h)
- Tractive Effort: 36kN
- Speed: 0 - 130km/h
- Rollers: 1,200mm diameter, 1,350mm centres
- Tyres: 700mm - 1,200mm diameter
- Road load simulation: vehicle inertias to 40kN, simulation of gradients +/-40kN
- Braking inertia: simulation up to 20T
- Max braking force: 200kN (=1g at 20T)
- Chamber ventilation: noise free extraction up to 3.5m/s aux fans for ram-air cooling
- Vehicle benchmarking, characterisation and design validation
- Investigation of noise and vibration performance (transmission path analysis, running mode analysis; NVH testing)
- Powertrain noise investigations
- Driveline and axle investigations
- Exhaust system noise and vibration measurement
- Disconnect exercises
- Acoustic transfer function measurement
- Exhaust system transmission loss/ insertion loss tests
- Driveline durability testing
- Driveline vibration investigations
- Acoustic testing of individual components requiring very low background noise
