ABSTRACT
One of the most troublesome and perhaps the most common noise source in industrial environments is the gas jet. This basic noise mechanism is often referred to as aerodynamic noise, and some examples include blowoff nozzles, steam valves, pneumatic control discharge vents, gas or oil burners, etc. To emphasize the word troublesome, the sound pressure level 3 ft from a typical 1/4 in. diameter shop air blowoff nozzle is often in the range of 105 to 107 dBA. As has been the practice throughout this text, this chapter considers briefly the basic physical parameters which determine the level and character of the noise mechanisms and then proceeds to the measures for noise control. The noise from furnaces, burners, and similar combustion equipment has its origin in complex interactions associated with high-velocity flow, turbulent mixing, and combustion. Several methods for predicting the magnitude and spectral character of burner noise have been developed, but the phenomenon is not well understood.
