High Combustion Research Articles

Comparative study on the adaptability of diesel/aviation kerosene in rotary engines

It is of great significance to compare the spray characteristics and combustion characteristics of aviation kerosene and diesel in rotary engine condition when looking for the alternative of diesel in rotary engines. In this paper, several combustion characteristics of diesel and aviation kerosene were obtained by spray experiment, including ignition characteristics, ignition delay period, flame floating length, and other combustion characteristics under rotary engine conditions. After that, a three-dimensional dynamic model of the rotary engine is established and verified by the experimental data. On this basis, the combustion process of diesel engine and aviation kerosene engine under different injection strategies is simulated. Normal ignition of diesel requires environmental conditions to reach 750 K/2.5 MPa, while aviation kerosene needs to reach 800 K/2.0 MPa to achieve stable combustion, which indicates that aviation kerosene has higher requirements for the environment. However, under the rotary engine condition, the atomization quality of aviation kerosene is better than that of diesel, and it has higher combustion, heat release and work capacity and faster flame propagation speed. Therefore, aviation kerosene can be used as the fuel of rotary engine instead of diesel. Especially in Case A3, the peak pressure in the combustion chamber of the aviation kerosene rotary engine reaches 38.89 bar, showing obvious advantages over the diesel rotary engine. In addition, the soot emissions of aviation kerosene engines are significantly lower than those of diesel rotary engines.

Experimental study on the characteristics of thermal runaway propagation process of cylindrical lithium-ion batteries

ABSTRACT This study examines the risks of thermal runaway in Lithium-ion batteries, especially under abusive conditions, which can lead to high temperatures, combustion, and explosions, posing safety threats. It focuses on thermal runaway propagation, temperature changes, propagation time, mass alterations, gas composition, and concentration shifts. Experiments were conducted on various Lithium-ion batteries with different SOCs. The results show inevitable thermal runaway in one-dimensionally arranged cylindrical Li-ion batteries. Higher SOC batteries have increased combustion risks, faster transfer rates, longer gas release, and produce irritating gases like NH3, HCl, and HF. Trigger temperatures and times vary with SOC: 100% SOC batteries trigger at 97°C in 185 s, while 25% SOC batteries trigger at 232°C in 299 s. The propagation time between adjacent batteries decreases from 273 s to 74 s as SOC increases from 25% to 100%. A predictive model is introduced to calculate peak temperatures and analyze propagation paths, enhancing understanding and safety considerations of thermal runaway in batteries.

Predicting transient performance of a heavy-duty gaseous-fuelled engine using combined phenomenological and machine learning models

Decarbonizing long-haul goods transportation poses a substantial challenge. High-efficiency natural gas (NG) engines, which retain the efficiency of a diesel engine but reduce the carbon content of the fuel, offer substantial potential for near-term greenhouse gas (GHG) reductions. A fast-running model that can predict engine performance, GHG and air pollutant emissions is critical to assessing this approach for different applications and vehicle drivetrain configurations. This paper presents the development, validation and application of an engine system model that adapts GT-SUITE™’s phenomenological DI-Pulse predictive model to predict the performance and emissions of a 6-cylinder NG engine using a high pressure direct-injection combustion process. The model includes the engine air exchange system, enabling the prediction of the engine and in-cylinder conditions and overall performance over transient drive cycles. The engine model with a fixed set of calibration parameters captures the complex high-pressure direct injection combustion process and generates time-resolved parameters that are fed into a coupled machine learning model to predict emissions, including nitrogen oxide (NOx) and methane (CH4) emissions. While the 1-D model’s predictions for CH4 were not accurate, coupling the 1-D engine model with a machine learning model has been shown to substantially improve the estimation of CH4 emissions and allow accurate prediction of engine total GHG emissions over different duty cycles. The model has been validated using transient engine dynamometer data and is then applied to assess performance and emissions over several regulatory and real-world long-haul drive cycles. The model showed an average error of less than 5% in steady operation. Cumulative errors of NOx and CH4 emissions in studied cycles were also less than 10%. The results showed that CH4 share in total GHG emissions ranges from 0.2% to 1.4% over various drive cycles. By predicting engine performance and emissions, the developed combined model has considerable potential for use in engine evaluation studies, especially when combined with new technologies across different duty cycles.

Catocene and Butacene Permanence as Ferrocenic Liquid Burning Rate Catalyst for Solid Composite Propellants and Comparison With Recent Developments

ABSTRACTA short review about ferrocene‐based burning rate catalysts (FBRC) for solid composite propellants is presented. Historically, transition metal oxides (TMO) have been utilized as burning rate catalysts (BRC) since the start of solid rocket propellant development. However, these compounds have a marked tendency to migrate through the propellant grain and crystallize at boundary surfaces. Consequently, FBRC emerged as an alternative to TMO. After reviewing recent advances in the field, we suggest that the continued use of Catocene [2,2′‐bis(ethylferrocenyl)propane] and Butacene as liquid BRC of choice is based on a trade‐off between high burning rates, limited migration from propellant, simpler synthetic pathways, and lower costs of production in comparison with later developments in the area of FBRC. Then, this work aims to contribute to the state of the art of FBRC research, highlighting the importance of Catocene and Butacene, in comparison with the most recent developments in the field of FBRC, particularly regarding their role in decreasing the decomposition temperature of ammonium perchlorate and/or increasing the burning rate.

Chemical kinetic analysis of multi-pollutant emissions from high temperature combustion of sewage sludge

Chemical kinetic analysis of multi-pollutant emissions from high temperature combustion of sewage sludge

A laboratory-scale simulation framework for analysing wildfire hydrologic and water quality effects

Background Wildfires can significantly impact water quality and supply. However logistical difficulties and high variability in in situ data collection have limited previous analyses. Aims We simulated wildfire and rainfall effects at varying terrain slopes in a controlled setting to isolate driver-response relationships. Methods Custom-designed laboratory-scale burn and rainfall simulators were applied to 154 soil samples, measuring subsequent runoff and constituent responses. Simulated conditions included low, moderate, and high burn intensities (~100–600°C); 10-, 200-, and 1000-year storm events (~14–51 mm/h); and 10–29° terrain slopes. Key results Simulators can control key drivers, with burn intensities highly correlated (R2 = 0.64) with heat treatment durations. Increasing burn intensity treatments generally saw significant (α = 0.05) increases in responses, with runoff and sedimentation increasing by ~30–70% with each intensity increment. Carbon and nitrogen peaked at moderate intensities (~250°C), however, with concentrations ~200–250% of unburned samples. Conclusions Distinct responses at each burn intensity indicate nuanced changes in soil physical and chemical composition with increased heating, exacerbating driving mechanisms of runoff and sedimentation while reducing carbon and nitrogen through volatilisation. Implications This work furthers our understanding of interactions between complex geographic features and the mosaic of burn intensities which exist in wildfire-affected landscapes.

Influence of Particle Size and Packing Density on Combustion of Compacted Nickel-Aluminum Powder Mixtures

ABSTRACT An experimental study is conducted to investigate the effects of particle size and packing density on the combustion of nickel-aluminum pellets. The particle sizes of Al and Ni are varied in the range of 1–25 µm, and the packing density is varied between 63% and 76% of the theoretical maximum density (TMD). The pellets are burned in a quartz tube, and the combustion process is recorded using a high-speed video camera. Temperature evolution during combustion is recorded, and the composition of burned pellets is analyzed. Computer simulations of the pellet combustion process are also conducted using a multiscale model, in which the diffusion process in the particles is coupled to energy transport in the pellet. Two distinct propagation modes are observed – (i) a quasi-steady mode characterized by high combustion velocities and continuous front propagation and (ii) a relay-race mode characterized by low combustion velocities and discrete jumps of the combustion front. The combustion velocity increased with decreasing Ni particle size due to a reduction in the length scale of the atomic diffusion process. Increasing the Al particle size generally increased the combustion velocity due to increased permeability of the pellet and reduced oxide content in the Al powder. The combustion velocity decreased by a factor of 3–4 when the packing density increased from 63% to 76% TMD. Super-adiabatic flame temperatures are not observed and the product analysis revealed the presence of intermediates (such as Ni2Al3) and layered structures in the burned pellets for the relay-race propagation mode. The study suggests that the combustion rate of Ni-Al pellets is strongly dependent on the rate of atomic diffusion processes, the oxide content in the powders, and the ability of the Al melt to wet the surface of Ni particles and preheat the unburned regions of the pellet.

INFLUENCE OF HYDROGEN ON COMBUSTION PROCESS AND ON EMISSION PARAMETERS IN THE RCCI ENGINE

Thanks to its carbon-free nature, it is possible to say that hydrogen is a potential fuel for future automotive systems. Its main favourable properties include high burning rate, wide range of flammability and low ignition energy. In combination with hybrid electric technology, the hydrogen combustion engine has the potential for further development with the goal of maximum efficiency in energy conversion. For more efficient hydrogen combustion, a dual fuel injection hybrid system is designed, where one injector is designed for direct hydrogen injection into the engine cylinder and the other injector is supply fuel to the engine's intake pipe. The greatest challenge is development of a control algorithm intended for management of the combustion process in hydrogen engine and optimization of fuel injection divided into individual doses.

Increasing the efficiency of a conversion gas turbine engine by adding hydrogen to fuel gas

Hydrogen, as a zero-carbon fuel, is becoming an important component for decarbonizing the economy. It can be used not only as a storage medium, but also as a fuel for power generation equipment. Hydrogen is very different in its energy properties (high calorific value, high combustion rate), which are very different from traditional gas turbine fuels, so when burning hydrogen, new unexplored problems may arise during the operation of main and auxiliary equipment.To introduce hydrogen technologies into the traditional energy system, new approaches to equipment operation are required. Gas turbines, unlike other power equipment, can be configured to burn any gaseous fuel that meets the requirements for the combustion chamber. Combustion of 100% H2 in the combustion chamber of an operating gas turbine is impossible without deep modernization; this can cause damage to the main and auxiliary equipment. Gas turbines powered by hydrogen will be an important component in the decarbonization of all industries.The article discusses the variable operating modes of a gas turbine unit with a capacity of 18 MW, depending on the percentage of H2 in natural gas. The traditional fuel for gas turbines is natural gas; the presented study considers adding up to 20% hydrogen to the original natural gas. The addition of hydrogen fuel affects the operating mode of the turbine. The operation of a gas turbine unit at various outside temperatures, operation at full and partial load in the conditions of the wholesale electricity market is considered.

Construction of an In Situ-Generated Nanoscale Organic-Inorganic Hybrid System Using Hydrogen Bonding Interaction To Assist Thermal Properties of Resins.

With the rapid development of science and technology, high-temperature-resistant resin systems are facing more severe challenges in extreme applications. To further improve the comprehensive thermal properties of phthalonitrile resins, an in situ generation of a high-temperature-resistant phthalonitrile resin achieving an organic-inorganic hybridization network is reported. A 3-aminophenol phthalonitrile containing -NH2 is used as a material to hybridize with prepared calcium phosphate nano-oligomers (CPOs), and the hybrid precursor is named as CAPN. Notably, the hydrogen bonding plays a crucial role in the hybrid, as nanosize control of CPOs, and in the synthesis of CAPN. The presence of hydrogen bonding interaction is proved by Fourier transform infrared, Raman, 31P solid-state nuclear magnetic resonance spectra, isothermal differential scanning calorimetric testing, and calculation of apparent activation energy (Ea). Based on organic-inorganic hybrid cross-linked networks formed by resins during the curing process, 50CAPN (the hybrid containing 50 wt % CPOs) has superior thermo-mechanical properties [glass transition temperature (Tg) > 580 °C] and thermal stability [5% pyrolysis temperature (Td5%(N2) = 574 °C, Td5%(air) = 543 °C)] than the blending system 50HAPN [the mixture with 50 wt % nanohydroxyapatite (HAP)]. Additionally, under extreme high temperature and combustion conditions, it demonstrates that 50CAPN has more stable thermo-oxidative aging resistance and flame retardancy than 50HAPN. We believe that this organic-inorganic hybrid system of phthalonitrile formed based on hydrogen bonding will elevate the introduction of the inorganic phase into the organic phase for the preparation of high-temperature-resistant resin systems to a certain level.

Advances in surface coating and performance enhancement of ammonium perchlorate

Abstract Ammonium perchlorate (AP), which has the advantages of high oxygen content, good thermal and chemical stability, and no solid residue after thermal decomposition, is considered to be the most widely used oxidiser for solid propellant applications. However, the high mechanical sensitivity, moisture absorption, and thermal decomposition temperature of AP seriously affect the performance of the solid propellant. In this paper, we systematically review the research progress of the improvement of desensitization, anti-hygroscopicity, and thermal decomposition performance by surface coating of AP. At the same time, the surface coating methods are focusing on electrospray technology, reduced pressure distillation, ultrasonic synthesis, liquid phase deposition, supercritical fluid, intermittent spray coating, and electrostatic self-assembly coating method. Among above, intermittent spray coating and liquid phase deposition method are the preferred surface coating method due to their uniformity of coating, ease of adhesion and good performance enhancement. It is expected that the research on surface coating and performance enhancement of AP can greatly promote the innovation and development of AP in the field of high burning rate solid propellant.

Enhancing Engine Cylinder Heat Dissipation Capacity Through Direct Optimization (DO) Techniques

Internal combustion (IC) engines are used widely as the primary power source for automobiles of all types, cars, motorcycles, and trucks. Because of the high combustion temperatures involved in the operation, the excess heat is removed by means of extended fins that increase the surface area for adequate cooling. Significant improvement in the heat dissipation characteristics of the engine cylinder can be achieved by optimizing the design of these fins. The aim of this study is to evaluate the thermal performance of engine cylinder fins using an analytical system of finite element analysis (ANSYS FEA) software, using a direct optimization (DO) approach to identify optimal fin design. Analysis shows that fin length and width play critical roles in improving cooling efficiency, lowering the maximum temperature within the cylinder to 549.46 K and enhancing total heat flux to 7225.31 W/m2, which is a 25.87% increase from the generic design, capable of heating removal of 5740.22 W/m2. The current fin design is effective but could be improved in heat dissipation, mainly at fin tips. To optimize thermal performance while minimizing material costs, a balanced fin dimension is recommended. Alternative materials, transient heating analysis, and experimental verification may be examined in the future to achieve a total understanding of fin geometry and behavior under real operating conditions. These insights lay a foundation to accelerate cooling systems development in the automotive, aerospace, and heavy equipment industries, where efficient heat transfer is key for performance and long-term durability.

High Throughput Solution Combustion Generated Nickel Oxide Films As a Hole Transport Layer for Perovskite Photovoltaics

Nickel oxide remains a prominent hole transport layer (HTL) for use in inverted perovskite photovoltaic devices owing to its high optical transmission as a thin film, hole mobility, and chemical tunability. Numerous approaches have been posited for forming high quality nickel oxide thin films with solution combustion synthesis (SCS) as one of the most promising to yield high quality oxide thin films at high throughputs. However, the resulting characterization of the nickel oxide generated can be challenging owing to nickel oxide’s surface reactivity under ambient conditions and its instability against common laboratory techniques such as X-ray photoelectron spectroscopy (XPS) with argon depth sputtering.Here, we present a multi-modal synchrotron radiation characterizations of nickel oxide thin films generated via solution combustion synthesis with a curing duration of 1 min at 300 ºC for perovskite solar cells. We explore the role of varying the ligand structure and fuel/oxidant ratio of the nickel oxide precursor and assess the resulting properties of the nickel atoms using extended X-ray absorption fine structure, ex situ X-ray absorption near edge spectroscopy, and grazing-incidence X-ray diffraction along with lab-scale XPS. We have also performed some of the first in situ analysis of the combustion process using synchrotron radiation with 5 second time resolution. As a result, we can provide unprecedented sensitivity to correlate between the chemical state of Ni in the film bulk and surface to device performance and stability.

Research Progress of Burning Rate Inhibitors in Solid Heterogeneous Propellants

AbstractThe advancement of solid rocket technology has increased demand for high‐performing propellants, particularly in the aerospace industry. Solid propellants are an essential component of rocket engines, and their stable combustion and adjustable burning rate throughout a wide pressure range significantly affect the performance of motors. The burning rate modifiers include catalysts and inhibitors. Solid rocket motors for different purposes require propellants with different burning rates. Using propellants that burn at a slower rate is beneficial for the smooth release of propellant energy, reducing the loss of energy in the process of high burning rate release and improving the endurance time of missile engines. Therefore, it is necessary to decrease the burning rate of propellant. This article summarizes the development of burning rate inhibitors (BRIs) and analyzes the mechanisms and behaviors of different BRIs, including amide‐based compounds, metal salts, and cationic surfactants, that affect the combustion of propellants.

Facile Synthesis and Decomposition Kinetics of Energetic Molecular Perovskite DAP-4 Catalyzed with Copper Nanoparticles for Advanced Energetic Systems

AbstractMolecular perovskite DAP-4 (NH4)(C6H12N2)(ClO4)3 can expose high oxidizing capability, with superior decomposition enthalpy compared with ammonium perchlorate (AP). DAP-4 was developed via molecular assembly method. The potential impact of copper nanoparticles (Cu NPs) on DAP-4 thermal decomposition was evaluated. Reactive Cu NPs of 50 nm were integrated into DAP-4 structure via solvent evaporation. Uniform dispersion of Cu NPs into DAP-4 matrix was assessed using elemental mapping. Whereas AP demonstrated decomposition enthalpy of 733 J/g; virgin DAP-4 and Cu/DAP-4 nanocomposite experienced decomposition enthalpy of 3800, and 4150 J/g respectively. Cu NPs offered decrease in DAP-4 main decomposition temperature by 49 oC. Decomposition kinetics was investigated via Kissinger, and Kissinger–Akahira–Sunose (KAS). Cu/DAP-4 demonstrated apparent activation energy of 134.97 ± 3.02 kJ/mol compared with 216.32 ± 4.42 kJ/mol for virgin DAP-4. Cu NPs offered decrease in DAP-4 combustion time from 70 ms to 31 ms, with high intense combustion flame. Copper NPs experienced dramatic change in DAP-4 decomposition mechanism from F1 to F3.Copper NPs could act as efficient reactive catalyst particles; that could be oxidized to CuO with the evolution of 3700 J/g. The evolved CuO nanocatalyst could boost decomposition enthalpy.

Before the fire: predicting burn severity and potential post-fire debris-flow hazards to conservation populations of the Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus)

Background Colorado River Cutthroat Trout (CRCT; Oncorhynchus clarkii pleuriticus) conservation populations may be at risk from wildfire and post-fire debris flows hazards. Aim To predict burn severity and potential post-fire debris flow hazard classifications to CRCT conservation populations before wildfires occur. Methods We used remote sensing, spatial analyses, and machine learning to model 28 wildfire incidents (2016–2020) and spatially predict burn severity from pre-wildfire environmental factors to evaluate the likelihood (%) and volume (m3) hazard classification of post-fire debris flow. Key results Burn severity was best predicted by fuels, followed by topography, physical ecosystem conditions, and weather (mean adjusted R2 = 0.54). Predictions of high or moderate burn severity covered 1.1 (15% of study area) and 1.5 (19% of study area) million ha, respectively, and varied by watershed. Combined high or moderate debris flow hazard classification included 80% of stream reaches with conservation populations and 97% of conservation population point nodes. Conclusions Predicted burn severity and potential post-fire debris flow indicated moderate to high hazard for CRCT conservation populations native to the Green and Yampa rivers of the Upper Colorado River Basin. Implications Future management actions can incorporate predicted burn severity and potential post-fire debris flow to mitigate impacts to CRCT and other at-risk resource values before a wildfire occurs.

Whistling potential of throttling orifices and its connection to liquid rocket combustion instability

Orifice whistling is recently established as a cause of high frequency combustion instability in liquid rocket engines. The series of studies on the experimental thrust chamber, known as BKD, developed at the German Aerospace Center (DLR), were instrumental in identifying this phenomenon. BKD encountered an injector-driven thermo-acoustic instability caused by the self-excitation of the LOX injector. The throttle orifice in the LOX injector plays a vital role in the self-excitation through whistling. In this work, the impedance of the BKD throttling orifice is characterized with the motive to find its whistling range. The CFD approach based on solving the unsteady Reynolds Averaged Navier Stokes equations proposed by Lacombe et al. [1] is used for this characterization. We characterize the orifice at the weak and the strong coupling conditions reported in the literature. The orifice impedance is calculated in the range of 4 kHz to 15 kHz, covering the entire potential coupling range of LOX injector eigen modes. The impedance results show that the orifice character follows the whistling behavior of the “medium” orifices. The resistance turns negative in the Strouhal number range of St=0.89 - 1.2 for both the weak and strong operating conditions. When plotted against the frequency, the resistance at the strong coupling condition occurs close to the second longitudinal (2L) mode of the LOX injector, suggesting direct excitation of the injector through the orifice whistling. The coexistence of the 2L mode and the first transverse (1T) mode of the combustion chamber at the same frequency leads to combustion instability.

Impacts of low-temperature heat release on unstretched laminar burning velocity in advanced flex-fuel gasoline-ethanol engines

Improving brake thermal efficiency (BTE) of flex-fuel engines can contribute to decarbonizing conventional and hybridized vehicles running on spark-ignited (SI) engines. High compression ratio (CR) and burning velocity under exhaust gas recirculation (EGR) conditions can improve the engine BTE. Ethanol fuel, which has been attracting increasing attention recently, can improve brake thermal efficiency due to its high-octane number and fast laminar burning velocity (LBV). With higher CRs, low-temperature heat release (LTHR) occurs in the unburned mixture, which affects the compositions, oxidation, and in-cylinder temperature. Such thermodynamic changes on unstretched LBV have not been thoroughly investigated, especially in production-intent next-generation flex-fuel engines. This study aims to clarify the LTHR impacts on LBV under EGR conditions using ethanol-blended gasoline surrogate fuel SI engines. The testbed used a single-cylinder SI engine fueled by E0 (gasoline surrogate), E20 (20 % ethanol + 80 % E0 by volume), E40, E60, E85, and E100. Detailed chemical reaction calculations were conducted using the boundary conditions obtained from production-intent, strong-tumble flow, and flex-fuel engine experiments. This work predicted LTHR in an unburned mixture using a zero-dimensional detailed chemical reaction calculation. LBV is predicted by a 1D kinetic laminar flame code. As a result, LTHR proceeds before the main combustion. The results show that the temperature increase associated with LTHR increases the burning velocity, while the partial oxidants decrease the burning velocity. Moreover, this work examined higher CRs using detailed chemical reaction calculations, and the results show that fuels with higher ethanol blending ratios can increase LBV in the late combustion phase.

State-of-the-art Advances in the Ignition Selay Reduction of N,N-dimethylethanamine

Propellant is a core fuel in defense and aerospace applications. However, conventional hydrazine fuel is highly volatile, toxic, and carcinogenic, resulting in huge threats to the human body and environment. N,N-dimethylethanamine (DMAZ) is a green, high-energy fuel with a low freezing point, high density, high specific impulse, and high combustion rate, and it is a promising substitute of conventional hydrazine fuel. Nevertheless, the industrial application of DMAZ is limited by long ignition delay. In this study, the mechanism of ignition of DMAZ was explored by summarizing current methods to reduce the ignition delay of DMAZ, including the addition of catalyst, fuel formulation, and tuning molecular structure. This study provides references for applications of amine azide.

In situ iron coating of amorphous boron and characterization of its energy release behavior

Boron was widely employed as metal fuel in solid propellants for its higher gravimetric and volumetric combustion enthalpies. However, the low melting point and high boiling point of B2O3 on the surface of boron particles significantly hinder its ignition and combustion performance, seriously preventing the full realization of its thermodynamic potential. To address this issue, B@Fe composite fuels with different iron contents from 1.59 % to 7.09 % were prepared via liquid phase reduction in this paper and the quasi-static high temperature oxidation, ignition and combustion reaction characteristics and corresponding mechanism were studied, in order to provide effective modification techniques in supporting the large-scale engineering application of boron as metal fuel. The study results show that B@Fe can effectively reduce the ignition temperature and maximum heat flow temperature of amorphous boron, and increase the maximum mass gain rate. The ignition temperature and maximum heat flow temperature have an exponential function with the iron coating content. Iron coated amorphous boron can effectively shorten the laser ignition delay time by more than 50 %, and significantly change the flame structure, flame evolution process and combustion duration. Both amorphous boron and iron-coated amorphous boron flame showed a multi-layer structure, including the outer green flame, the middle yellow flame and the central incandescent flame. However, with the increase of the iron coating content, the flame height increased from 5.5 cm to 6.3 cm, the flame structure changed from mushroom type to triangle type, and the central incandescent flame area increased significantly. The equivalent combustion duration increased from 975 ms to 1997 ms, and the flame temperature increased from 1288 to 1505 °C. The emission spectra of BO2 and BO lines are captured during combustion. B@Fe with the increase of iron content, a large number of small diameter micropores appear in the condensed combustion products(CCPs) of composite fuels, and a grid-like structure was formed. With the increase of iron coating content, the boron content of condensed combustion products decreases, and the oxygen content increases. The main components of CCP include B, B2O3, B6O, FeB, Fe2B and Fe3B. Based on the ignition combustion experiment of B@Fe composite fuel, ignition combustion analysis model of B@Fe composite fuel was established.