Combutsion Kinetic Experiments
Introduction
The accuracy and reliability of experimental data are the cornerstone of constructing and verifying combustion models, having a decisive impact on the development of combustion science and technological innovation. Reaction kinetics experiments provide us with direct evidence of the rates and mechanisms of chemical reactions during combustion. Moreover, it plays an irreplaceable role in validating and refining theoretical models, optimizing combustion technologies, and controlling pollutant emissions.
Our research group covers the shock tube pyrolysis and combustion experiments and flame propagation tests for a variety of fuels in the field of reaction kinetics experiments. The experimental subjects include gasoline, aviation kerosene, bio-kerosene, hydrazine fuels, energetic materials, and propellants. Through these experiments, we have investigated the combustion characteristics of different fuels under various conditions, including their ignition delay times, the distribution of pyrolysis products and the laminar flame speed. These studies not only help us understand the combustion behavior of fuels but also have significant importance for verifying and optimizing reaction kinetics models.
Ignition Delay Time Measurements
The ignition delay time is the time interval between the excitation of the ignition source and the start of self-sustained combustion of the fuel. The experimental study of the ignition delay time of the excitation tube is essential for understanding the kinetics of chemical reactions during combustion. These data can provide experimental validation of reaction kinetics models.
Fig. 1. Scheme diagram of high pressure shock tube (HPST) system (left) and definition of the ignition delay time (right). (X. Ren, Y. Li*, et al. Fuel 375 (2024) 132623.)
Fig. 2. IDT measurements of (a) TKX-50 and (b) HMX. (X. Ren, Y. Li*, et al. Fuel 375 (2024) 132623.)
Single Pulse Speciation Measurements
The single pulse shock tube technique allows us to simulate the pyrolysis of fuels at high temperatures and pressures in milliseconds, thus obtaining the distribution of pyrolysis products. These data can also provide experimental validation of pyrolysis kinetic models of fuels.
Fig. 3. Scheme diagram of single pulse shock tube (SPST) system.
Fig. 4. Concentration distribution of pyrolysis products for the full formulation of NEPE propellant. (On working)
Laminar Flame Speed Measurements
Our group also conducted laminar flame speed measurements by the fixed-capacity combustion bomb combined with high-speed camera technology. This parameter not only helps to reveal the combustion mechanism under different combinations of fuels and oxidizers, but also provides an experimental benchmark for numerical simulation of the combustion process
Fig. 5. Scheme diagram of laminar flame speed experimental system
Fig. 6. Experimental records diagram of spherical flame propagation test for DME/N2O/N2. (Under reviewing at the journal of Combustion and Flame)
Development of novel experiments
In addition, in order to achieve comprehensive and versatile characterization of reaction kinetic experiments, our group is also sequentially developing the experiments of solid propellant laser ignition(to be confirmed), visualized shock tube ignition, and self-ignition propellant titration/hedge ignition.
Fig. 7. Visualized shock tube.