page 1 5th meeting of grb informal group ‘asep’ potentials of exhaust systems with valves filip...
TRANSCRIPT
![Page 1: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/1.jpg)
Page 1
5th meeting of GRB Informal Group ‘ASEP’
Potentials of exhaust systems with valves
Filip Dörge
![Page 2: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/2.jpg)
Page 2
Valves in exhaust systems : general overview of possible acoustical efficiency improvements
Flow noise
Engine noise
Back pressure
Passive exhaust systems
Exhaust systems with a valve
Passive exhaust systems
Exhaust systems with a valve
![Page 3: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/3.jpg)
Page 3
Valve closed at low exhaust gas volume flow
valve opens automatically at high exhaust gas volume flow
Example of a silencer equiped with an auto-actuated valve
![Page 4: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/4.jpg)
Page 4
Example 1: FLOW NOISE REDUCTION(engine noise and backpressure unchanged)
6 dB
Valve opens here
Passive exhaust system
Exhaust system with a valve
SP
L [d
B(A
) at
50c
m]
Engine speed [rpm]
![Page 5: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/5.jpg)
Page 5
Example 2: ENGINE NOISE REDUCTION(flow noise and backpressure unchanged)
Valve opens here
Passive exhaust system
Exhaust system with a valve
SP
L [d
B(A
) at
50c
m]
Engine speed [rpm]
![Page 6: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/6.jpg)
Page 6
Example of an exhaust system equipped with an auto-actuated valve and with BY-PASS OF THE REAR SILENCER
Valve
by-passing the rear silencer
at high rpm’s
Catalytic
converters
Front silencer Rear silencer
![Page 7: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/7.jpg)
Page 7
View on the measured prototype exhaust system
Valve
by-passing the rear silencer
at high rpm’s
Catalytic
converters
Front silencer Rear silencer
![Page 8: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/8.jpg)
Page 8
Test results
by pass closed
by pass open
Switch point
![Page 9: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/9.jpg)
Page 9
Test results
Campbell diagram: colours indicate sound level
frequency [Hz]
Eng
ine
spee
d [r
pm]
by pass closed by pass open
frequency [Hz]
dB(A)
70
20
dB(A)
70
20
6000
1000
0 5000 0 5000
![Page 10: Page 1 5th meeting of GRB Informal Group ‘ASEP’ Potentials of exhaust systems with valves Filip Dörge](https://reader036.vdocuments.net/reader036/viewer/2022062715/56649dac5503460f94a9b461/html5/thumbnails/10.jpg)
Page 10
THANK YOU !