Investigation On The Spray Combusion Process Of Kerosene Gel Containing Metal Particles

Gel are new class of liquid fuels whose rheological properties have been altered by the addition of gellant [1].They show a semi-solid state at room temperature.However,when the environment is altered,they can also flow like liquid.The viscoelastic properties increase safety by reducing the possibility of accidental leakage.Furthermore,metal particles,such as boron,aluminum,magnesium,and iron,can also be employed as additives in gel without sedimentation to increase density specific pulse This article is based on the background of the application of kerosene gel containing metal particles in ramjet engines.It aims to recognize the characteristics of the metal particle gel and lay the foundation for the subsequent development of the overall design of the metal particle gel engine.The preparation of kerosene gel was first carried out,as well as the preparation of the metallized kerosene gel.The polyamide resin is successfully used to achieve the gelation of kerosene,and a two-step method was used to solve the sedimentation of metal particles.Subsequently,the physical and chemical properties of the prepared kerosene gel containing metal particles were studied.The stability is evaluated first,which proves that the kerosene gel containing different concent of metal particles prepared in this paper can meet the practical requirements.Subsequently,the energy density,viscosity,surface tension and other properties of the metallized kerosene gel were calculated and measured,and the properties of the gel were further acknowledged.Experimental study on the combustion characteristics of a single kerosene gel droplet containing metal particles was carried out.A coflow burner was used to generate high-temperature viitated gas environment.According to the results,the combustion process of a single kerosene gel droplet containing metal particles can be divided into four stages,namely the gellant layer formation stage,the micro-explosion stage,the gellant combustion stage,and particle combustion stage.Besides,particle properties,gel composition,and environmental conditions are some of the key factors that affect the combustion process of a single kerosene gel droplet containing metal particles.The formation mechanism of the gellant layer is mainly affected by the thermal environment;the micro-explosion mechanism is affected by the structure of the gel layer;agglomerate combustion of the metal particles in the droplet may took place or not according to the different properties of metal particles.The spray combustion process of kerosene gel containing metal particles were also investigated.According to experimental results,the spray flame of kerosene gel containing metal particles can be divided into two zone,namely,the particle heating zone and the particle combustion zone.At the outlet of the nozzle,the spray flame is mainly due to the combustion of kerosene,however the particles were continuously heated by the hot coflow and kerosene spray flame.When the temperature of the particles reaches a certain temperature,they starts to combust.The combustion of metal particles mainly occurs downstream of the flame.The micro-explosion was observed near the nozzle outlet,which indicated that the micro-explosion still exists during the spray combustion process of kerosene gel containing metal particles.The results indicate that the addition of metal particles can reduce the lift-height of the spray flame and enlarge the flame length and width.Finally,the temperature distribution of th spray flame of kerosene gel containing boron particles was measured.The multi-wavelength measurement method and TDLAS technology were both used to carry out preliminary measurements of the particle phase surface temperature and the gas flow field temperature during the spray combustion process.The influence of environment condition and metal particle concentration were studied.Based on the flame temperature distribution of the kerosene gel spray,the mechanism of the spray combustion process of kerosene gel containing metal particles is further understood.