Method and apparatus for sound testing mufflers

Patent · Tue Jun 30 04:00:00 EDT 1987

OSTI ID:6188709

Wagner, W M; Bethke, T A

An apparatus is described for producing operating conditions and measuring sound of an operable vehicle during a stationary simulated drive-by test. The apparatus comprises: an actual vehicle including wheels and means for driving the wheels. The driving means includes an engine with means for exhausting gases including a muffler with driving means disconnected with respect to driving wheels; a dynamometer; means attached to the actual vehicle for connecting the dynamometer to the driving means; means for controlling the dynamometer to simulate operational loading of the engine; means for measuring sound, the measuring means including: regularly spaced microphones along a first line parallel to and spaced from a second line in an imaginary direction of travel; and means for at least partially shielding sound, the muffler unshields means with respect to the microphones. The shielding means shields much of the sound from the driving means, except from the muffler, so that the sound means measures primarily muffler sound in the operational environment even though vehicle is not moving. The dynamometer and controlling means simulates operational loading of the engine.

• Assignee: Donaldson Co., Inc., Minneapolis, MN
• Patent Number(s): US 4676111
• OSTI ID: 6188709
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330603 -- Vehicle Design Factors-- Engine System
330700* -- Advanced Propulsion Systems-- Emission Control
CONTROL
DYNAMOMETERS
ENGINES
MEASURING INSTRUMENTS
NOISE POLLUTION CONTROL
OPERATION
PERFORMANCE TESTING
POLLUTION CONTROL
SOUND WAVES
SPACE DEPENDENCE
STEAM MUFFLERS
TEST FACILITIES
TESTING
VEHICLES