| The purpose of this project was to develop a sensor to measure the sound speed of a gaseous medium in an automotive environment. The sound speed of a gas can be related to a number of important properties such as gaseous fuel quality or gas concentration. This thesis describes the development of a novel acoustic technique called the discrete acoustic wave and phase detection (DAWPD) method for measuring sound speeds with path lengths on the order of millimeters. Experimental results are used to prove that the DAWPD method can provide accurate measurements over short path lengths. Sources of error are also identified and discussed. Possible automotive applications are discussed and tested. These applications include: a natural gas quality sensor, a variable gaseous fuel concentration sensor and an exhaust gas recirculation sensor. |
