A technique that expands the OH-LIF thermometry range is developed. The PLIF of OH from dissociation of water in gas phase is used for temperature measurement both in flame and room air. The thermometry results from photo fragmentation laser induced fluorescence (PF-PLIF) at time delay from 200ns to 1ms after dissociation agree well with results from PLIF of OH from burning which are calibrated by CARS thermometry. And the results in room air agree with environment temperature at time delay from 50ns to 0.2ms. These two results validate the PF-PLIF thermometry method both in flame and room temperature, which allowing thermometry at low temperature or non-reaction region. At last the PF-PLIF was applied in a jet flow, and the temperature results from PF-PLIF, PLIF and CARS at different height of jet were compared.

In order to improve extraction ability of the two-dimensional HTV grid experiment data and achieve rich flow field velocimetry data. In this paper, a two-dimensional grid extraction method combining cross ponits and grid lines is proposed. A template indirect correlation method was used to extract the position of cross ponits. Based on the vector position information of cross ponits, two-dimensional inversion of convective field velocity is achieved by using the method of skeleton extraction with directional template. This method not only can extend the inversion data, but also can be used in the scramjet combustion flow field, that the relative uncertainty of calculation speed is optimized from 0.8% to 0.17%.

This paper summarizes the direct observation of tagged hydroxyl within 200 µs after its formation in the temperature range of 294 K–891 K. We estimate the time and temperature frame of the coexistence of chemical reactions and diffusion based on analysis of the behavior of the tagging fluorescence spot of photodissociation hydroxyl. The reasons for the existence of chemical reactions and interactions between chemical reactions and diffusion are then analyzed. Theoretical and experimental identification of this frame can be explored for non-contact spectral measurements based on hydroxyl in a general flow field.