Influence of measure-density on combustor characteristics

The apparatus of scan measurement was used to gather the temperature pattern at the combustor outlet, where the average working temperature of gas was about 1700K and the maximum temperature was about 1950K. Consequently, the measurement part was cooled by water or air. Usually, for intermittent measurement devices, the interval of circle angel could be changed to get a high-density temperature distribution. A continuous measurement manner was adopted to get point in circle. The angle between two measure-points was 1.286°.The annular combustor outlet was about 40 to 50mm in height, where 5 or 6 measure points were usually arranged. In this device, 10 measure points were arranged in a range of 45.5mm. Four thermocouples were arranged in circle to obtain 2800 measure-points of the temperature field in a single experiment. Data were drawn from the whole datasheet at intervals. Each group of data whose number decreased in turn, included temperature points of 2800, 1400, 700, and 350, respectively. Several groups of temperature distributions with different densities were established. Subsequently, data processing was conducted to calculate the main combustor characteristics, including arithmetic or integral average temperature, OTDF (overall temperature distribution factor) and RTDF(radial temperature distribution factor). It is found that the data from different groups with different measuring densities result in significant difference on the combustor characteristics. The veracity of temperature characteristics increases with the growing measure-density.