Add to ORKGAn improved method for the design of expansion-chamber mufflers is described and applied to the task of reducing exhaust noise generated by a helicopter. The method is an improvement of standard transmission-line theory in that it accounts for the effect of the mean exhaust-gas flow on the acoustic-transmission properties of a muffler system, including the termination boundary condition. The method has been computerized, and the computer program includes an optimization procedure that adjusts muffler component lengths to achieve a minimum specified desired transmission loss over a specified frequency range. A printout of the program is included together with a user-oriented description.Prepared at Langley Research Center.Cover title.Bibliog...
November 1971Includes bibliographical references (p. 52)The relationship between noise reduction and...
Accurate prediction of pressure pulsations in an engine is required because of the fact that these p...
A field noise measurement program has been conducted using both a standard SH-3A helicopter and an S...
An improved method for the design of expansion-chamber mufflers is described and applied to the task...
This paper shows the details of measurement of the acoustical transmission loss of single expansion ...
The world used several solutions exhaust systems of motor vehicles. Today, in addition to the core f...
A substantial quantity of research on muffler design has been restricted to a low frequency range us...
Attenuation characteristics of four different resonator mufflers were determined in both cold tests ...
Mufflers are widely used in engine exhaust systems for providing sound attenuation in a specific fre...
With the advancements in quiet engine technology, reduction of the fan noise sources, and use of hig...
Analytical methods were developed and/or adopted for calculating helicopter component noise, and the...
The purpose of this study is to improve the design of exhaust systems for internal combustion engine...
Exhaust noise in engines has always been a major source of automotive noise. Challenges for muffler ...
This paper describes the design, development and validation of a muffler for reducing exhaust noise ...
At present, a study on the end corrections of extended inlets and outlets of expansion chamber gas m...
November 1971Includes bibliographical references (p. 52)The relationship between noise reduction and...
Accurate prediction of pressure pulsations in an engine is required because of the fact that these p...
A field noise measurement program has been conducted using both a standard SH-3A helicopter and an S...
An improved method for the design of expansion-chamber mufflers is described and applied to the task...
This paper shows the details of measurement of the acoustical transmission loss of single expansion ...
The world used several solutions exhaust systems of motor vehicles. Today, in addition to the core f...
A substantial quantity of research on muffler design has been restricted to a low frequency range us...
Attenuation characteristics of four different resonator mufflers were determined in both cold tests ...
Mufflers are widely used in engine exhaust systems for providing sound attenuation in a specific fre...
With the advancements in quiet engine technology, reduction of the fan noise sources, and use of hig...
Analytical methods were developed and/or adopted for calculating helicopter component noise, and the...
The purpose of this study is to improve the design of exhaust systems for internal combustion engine...
Exhaust noise in engines has always been a major source of automotive noise. Challenges for muffler ...
This paper describes the design, development and validation of a muffler for reducing exhaust noise ...
At present, a study on the end corrections of extended inlets and outlets of expansion chamber gas m...
November 1971Includes bibliographical references (p. 52)The relationship between noise reduction and...
Accurate prediction of pressure pulsations in an engine is required because of the fact that these p...
A field noise measurement program has been conducted using both a standard SH-3A helicopter and an S...