Understanding Aga Report No. 10 – Natural Gas Speed Of Sound

Author: Jerry Paul Smith, Joel ClancyDownload File

The speed of sound in natural gas is the velocity a sound wave travels in the gas. There are a number of gas properties that affect the speed of sound and they include the composition of the gas, the pressure of the gas, and the temperature of the gas. The American Gas Association (AGA) Report No. 10, Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases, provides an accurate method for calculating the speed of sound in natural gas and other related hydrocarbon fluids.
Purpose of AGA Report No. 10
The development of ultrasonic flow meters prompted the development of AGA Report No. 10 (AGA-10). The ultrasonic meter determines the speed of sound in the gas as it calculates the flow of gas through the meter. In order for one to check the accuracy of the speed of sound measured by the ultrasonic meter, it was necessary to have an accurate method to calculate the speed of sound in natural gas. AGA-10 was developed to do just that. The speed of sound calculated by the method in AGA-10 compares very favorably to the speed of sound determined by the highly accurate research that was the basis for the report. The information in AGA-10 is not only useful for calculating the speed of sound in natural gas, but also, other thermodynamic properties of hydrocarbon fluids for other applications, such as the compression of natural gas and the critical flow coefficient represented by C*.