Xiaosong Wu

Experimental investigation of multi-cycle pulse detonation engine at different air inlet systems

To improve operation stability of pulse detonation engine and shorten the distance of deflagration to detonation transition, a series of multi-cycle detonation experiments were investigated with six different air inlet systems. Using air as oxidizer and liquid C8H18 as fuel, the effect of different air inlet systems on pulse detonation engine with frequency of 14 Hz and equivalence ratio of 1.5 was analyzed. Pressure history along detonation tube was recorded by five dynamic piezoelectric pressure transducers. It was approved by a particle image velocimetry that centrifugal forces from rotating airflow had a significant negative impact on the uniformity of fuel distribution in detonation tube. Furthermore, the experimental results indicated that operation stability of pulse detonation engine was increased with the improvement of fuel distribution, and deflagration to detonation transition distance was obviously decreased with the increase of thrust wall sealing. In these different air inlet systems, the pulse detonation engine with air inlet system of reed valve achieved the shortest deflagration to detonation transition distance, the best stability and stable operation of about 1 min at 14 Hz. This study provided references for the development of pulse detonation engine.

Research and Design of Ignition System of Pulse Detonation Engine

In order to study the influence of ignition parameters on the operation performance of pulse detonation engine, an adjustment both in ignition energy and frequency ignition system was researched. Based on the study of topologies of power electronics, the buck DC/DC converter was adopted in adjusting input voltage, and an LCC series–parallel resonant inverter with step-up transformer was applied in boosting voltage while power transistors were employed in controlling the spark frequency to design the semiconductor low voltage-high energy ignition system. The control circuits of the main circuit and frequency controlling unit were also particularly designed. The analytical model of the converter is based on the basic circuit theories and the normalized averaging technique. The simulations of the circuit by MATLAB/Simulink show that both ignition energy and ignition frequency are controllable as expected, so the new designed system can meet the PDE’s requirements of the initiation system.

Experimental Investigation of a Reed Valve on the Performance of a Pulse Detonation Engine

Abstract Valve system is an important part of pulse detonation engine (PDE). The purpose of this research was to demonstrate the feasibility of utilizing a reed valve to inject fuel/air mixture into the combustion chamber of a Pulsed Detonation Engine (PDE). Using air as oxidizer and liquid C8H18 as fuel, a series of multi-cycle detonation experiments were investigated. The experimental results indicated that the reed valve was able to realize supply control of single-tube PDE effectively, and achieved stable operation about 3 minutes at 12.5 Hz for 0.15 mm valve sheet and 30° limit baffle plate. The response time and total pressure recovery coefficient of the reed valve were influenced by valve sheet thickness and air mass flow rate. For 0.1 mm valve sheet and 45° limit baffle plate, the service life of valve sheet strikingly shortened. Some factors such as the valve sheet thickness, air mass flow rate and the limit baffle plates angle, should be comprehensively considered to design a reed valve.