Research on filling process of fuel and oxidant during detonation based on absorption spectrum technology

Abstract

Research on detonation process is of great significance for the control optimization of pulse detonation engine. Based on absorption spectrum technology, the filling process of fresh fuel and oxidant during detonation is researched. As one of the most important products, H 2 O is selected as the target of detonation diagnosis. Fiber distributed detonation test system is designed to enable the detonation diagnosis under adverse conditions in detonation process. The test system is verified to be reliable. Laser signals at different working frequency (5Hz, 10Hz and 20Hz) are detected. Change of relative laser intensity in one detonation circle is analyzed. The duration of filling process is inferred from the change of laser intensity, which is about 100~110ms. The peak of absorption spectrum is used to present the concentration of H 2 O during the filling process of fresh fuel and oxidant. Absorption spectrum is calculated, and the change of absorption peak is analyzed. Duration of filling process calculated with absorption peak consisted with the result inferred from the change of relative laser intensity. The pulse detonation engine worked normally and obtained the maximum thrust at 10Hz under experiment conditions. The results are verified through H 2 O gas concentration monitoring during detonation.

Experimental research on operation performance and acoustic behavior of two-phase dual-tube pulse detonation engine

“…Once the filling process of the mixture of fresh fuel and oxidant is measured, the fill fraction can be calculated. In order to measure the absorption peak of H 2 O in the laser absorption spectrum signal during the fill process, the H 2 O measurement system based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) 22 is designed in this paper.…”

Research on Optical Diagnostic Method of PDE Working Status Based on Visible and Near-Infrared Radiation Characteristics

“…As the content of H 2 O in the detonation product is obviously higher than that in the mixture of fresh fuel and oxidant, the content of H 2 O can be used as the object to determine the fill process. In order to study the radiation characteristics of gas-liquid two-phase PDE under different fill fractions, the fill fraction measurement system of PDE was built based on a single optical path fiber distributed laser absorption spectroscopy [27], as shown in Figure 2b. The laser with center wavelengths of 1391.67 nm was selected to measure the absorption peak of H 2 O.…”