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ACOUSTICAL DEMANDS AND SOLUTIONS FOR AN UNIVERSAL HIGH POWER MAINLINE LOCOMOTIVE (LOCOMOTIVE 2000)
Journal of Sound and Vibration (1996) 193(1), 435–436
ACOUSTICAL DEMANDS AND SOLUTIONS FOR AN UNIVERSAL HIGH POWER MAINLINE LOCOMOTIVE (LOCOMOTIVE 2000) M. H SLM AG, CH-8401 Winterthur, Switzerland (Received in final form 20 November 1995)
For universal mainline locomotives there are two difficult acoustic conditions: at high speed; at low-speed with high traction force. For analysis purposes some array measurements [1] were made at different running conditions. Up to 230 km/h there are no significant aerodynamic noise sources. Wheel/rail noise dominates, but there are some significant differences between the two wheels of each wheelset, resulting from the drive mechanism attachments. The directly driven wheel is less noisy because of better damping by rubber pads. At low speeds the wheel/rail noise is small. However, other sources such as gear noise, ventilation noise and wheel squeal under bad adhesion conditions may dominate. The optimization of the acoustical characteristics of the gear box was supported by intensity measurements on a test rig for the entire gear transmission path. Modern electric converter locomotives have a considerable demand for cooling air, more than 3 m3/s/MW. The locomotive 2000 therefore is supplied with or without the option of ventilation noise mufflers. At the centre of the locomotive 7·5 m from the centerline, and 1·2 m above the rail top level, the sound pressure is 84 dB(A) without and 74 dB(A) with ventilation mufflers [2, 3]. With bad adhesion conditions, caused mainly by wet rails, significant wheel creep—often more than 5 km/h—is needed to reach the maximum traction force possible. This huge
Figure 1. Locomotive 2000, SBB 460, V=80 km/h (y = 7·5 m, z = 1·2 m). LpfAmax = 79·0 dB(A); LpfAeq(0·83s) = 81·5 dB(A); LpfAeq(300s) = 55·9 dB(a); SEL = 800 dB(A).
435 0022–460X/96/210435 + 02 $18.00/0
7 1996 Academic Press Limited
436
.
difference between absolute velocity of the vehicle and circumferencial velocity of the wheel causes macroslip squeal. This arises typically with undamped wheels. With wheel dampers applied, however, a noise reduction of up to 35 dB(A) can be achieved. Up to the present time 179 type 2000 locomotives have been ordered: 119 by SBB, 18 by BLS (both Switzerland), 20 by VR in Finland and 22 by NSB in Norway. The majority of these locomotives are running and are proving that it is possible to stay below the strict Swiss noise limits of Lpmax = 80 dB(A) + 30 log (V/80 km/h) at a 7·5 m distance from the center of the track under regulated conditions. See Figure 1. REFERENCES 1. H. Z, H. R. G and M. H 1993 Schweizer Eisenbahnrevue 10/1993, 451–453. Die Reihenrichtmikrofon-Messtechnik, eine neue Methode zur gezielten Aussenla¨rmminderung. 2. M. H and B. K 1993 Schweizer Eisenbahnrevue 9/1993, 396–399. La¨rmarme umrichterund Fahrmotorventilation der SBB Re 460. 3. M. H and H. Z 1995 ZEV/DET Glasers Annalen 119, Heft 9/10. La¨rmdesign moderner Triebfahrzeuge am Beispiel der Lok 2000-Familie, Anwendung von Telemetrie, Intensita¨ts- und Arraymesstechnik.
ACOUSTICAL DEMANDS AND SOLUTIONS FOR AN UNIVERSAL HIGH POWER MAINLINE LOCOMOTIVE (LOCOMOTIVE 2000) M. H SLM AG, CH-8401 Winterthur, Switzerland (Received in final form 20 November 1995)
For universal mainline locomotives there are two difficult acoustic conditions: at high speed; at low-speed with high traction force. For analysis purposes some array measurements [1] were made at different running conditions. Up to 230 km/h there are no significant aerodynamic noise sources. Wheel/rail noise dominates, but there are some significant differences between the two wheels of each wheelset, resulting from the drive mechanism attachments. The directly driven wheel is less noisy because of better damping by rubber pads. At low speeds the wheel/rail noise is small. However, other sources such as gear noise, ventilation noise and wheel squeal under bad adhesion conditions may dominate. The optimization of the acoustical characteristics of the gear box was supported by intensity measurements on a test rig for the entire gear transmission path. Modern electric converter locomotives have a considerable demand for cooling air, more than 3 m3/s/MW. The locomotive 2000 therefore is supplied with or without the option of ventilation noise mufflers. At the centre of the locomotive 7·5 m from the centerline, and 1·2 m above the rail top level, the sound pressure is 84 dB(A) without and 74 dB(A) with ventilation mufflers [2, 3]. With bad adhesion conditions, caused mainly by wet rails, significant wheel creep—often more than 5 km/h—is needed to reach the maximum traction force possible. This huge
Figure 1. Locomotive 2000, SBB 460, V=80 km/h (y = 7·5 m, z = 1·2 m). LpfAmax = 79·0 dB(A); LpfAeq(0·83s) = 81·5 dB(A); LpfAeq(300s) = 55·9 dB(a); SEL = 800 dB(A).
435 0022–460X/96/210435 + 02 $18.00/0
7 1996 Academic Press Limited
436
.
difference between absolute velocity of the vehicle and circumferencial velocity of the wheel causes macroslip squeal. This arises typically with undamped wheels. With wheel dampers applied, however, a noise reduction of up to 35 dB(A) can be achieved. Up to the present time 179 type 2000 locomotives have been ordered: 119 by SBB, 18 by BLS (both Switzerland), 20 by VR in Finland and 22 by NSB in Norway. The majority of these locomotives are running and are proving that it is possible to stay below the strict Swiss noise limits of Lpmax = 80 dB(A) + 30 log (V/80 km/h) at a 7·5 m distance from the center of the track under regulated conditions. See Figure 1. REFERENCES 1. H. Z, H. R. G and M. H 1993 Schweizer Eisenbahnrevue 10/1993, 451–453. Die Reihenrichtmikrofon-Messtechnik, eine neue Methode zur gezielten Aussenla¨rmminderung. 2. M. H and B. K 1993 Schweizer Eisenbahnrevue 9/1993, 396–399. La¨rmarme umrichterund Fahrmotorventilation der SBB Re 460. 3. M. H and H. Z 1995 ZEV/DET Glasers Annalen 119, Heft 9/10. La¨rmdesign moderner Triebfahrzeuge am Beispiel der Lok 2000-Familie, Anwendung von Telemetrie, Intensita¨ts- und Arraymesstechnik.