Axial Injection Research Articles

Refueling of field-reversed configuration core via axial plasmoids injection

This study successfully developed a refueling technique for a field-reversed configuration (FRC) via axial plasmoid injection and demonstrated it on the FAT-CM device at Nihon University. The target FRC is generated using the collisional-merging formation technique combined with conical theta-pinch formation. Plasmoids with an FRC-like configuration are coaxially injected from both ends of the FAT-CM device toward the preexisting target FRC. Postinjection, the system achieves equilibrium, resulting in increases by factors of 1.8 and 2.4 in the total inventory and plasma energy, respectively, compared to cases without injection. This method effectively accomplishes FRC refueling while preserving the intrinsic characteristics of a simply connected, axisymmetric configuration and a high beta value approaching unity. Therefore, this approach offers potential for repetitive refueling in the reactor stage having a FRC plasma core. Experimental outcomes are compared with magnetohydrodynamic simulation results. In the collisional merging process, the characteristics of the pre-collision plasmoids, such as the strong toroidal rotation and coherent FRC-like magnetic field structures of the FRC, are not preserved. Experimental environments have been constructed to investigate such unique properties of the resulting FRCs.

Experimental Investigation of a H2O2 Hybrid Rocket with Different Swirl Injections and Fuels

Hybrid rockets have very interesting characteristics like simplicity, reliability, safety, thrust modulation, environmental friendliness and lower costs, which make them very attractive for several applications like sounding rockets, small launch vehicles, upper stages, hypersonic test-beds and planetary landers. In recent years, advancements have been made to increase hybrid motor performance, and two of the most promising solutions are vortex injection and paraffin-based fuels. Moreover, both technologies can be also used to tailor the fuel regression rate, in the first case varying the swirl intensity, and in the second case with the amount and type of additives. In this way, it is possible not only to design high-performing hybrid motors, but also to adjust their grain and chamber geometries to different mission requirements, particularly regarding thrust and burning time. In this paper, the knowledge about these two technical solutions and their coupling is extended. Three sets of experimental campaigns were performed in the frame of the Italian Space Agency-sponsored PHAEDRA program. The first one investigated a reference paraffin fuel with axial and standard vortex injection. The second campaign tested vortex injection with low values of swirl numbers down to 0.5 with a conventional plastic fuel, namely polyethylene. Finally, the last campaign tested another, lower regressing, paraffin-based fuel with the same low swirl numbers as the second campaign.

Performance of Atmospheric Plasma-Sprayed Thermal Barrier Coatings on Additively Manufactured Super Alloy Substrates

This work represents a preliminary study of atmospheric plasma-sprayed (APS) Yttria-Stabilized Zirconia (YSZ)-based thermal barrier coatings (TBCs) deposited on forged and additive manufactured (AM) HAYNES®282® (H282) superalloy substrates. The effect of different feedstock morphologies and spray gun designs with radial and axial injection on APS-deposited YSZ layer characteristics such as microstructure, porosity content, roughness, etc., has been investigated. The performance of TBCs in terms of thermal cycling fatigue (TCF) lifetime and erosion behaviour were also comprehensively investigated. In view of the high surface roughness of as-built AM surfaces compared to forged substrates, two different types of NiCoCrAlY bond coats were examined: one involved high-velocity air fuel (HVAF) spraying of a finer powder, and the other involved APS deposition of a coarser feedstock. Despite the process and feedstock differences, the above two routes yielded comparable bond coat surface roughness on both types of substrates. Variation in porosity level in the APS topcoat was observed when deposited using different YSZ feedstock powders employing axial or radial injection. However, the resultant TBCs on AM-derived substrates were observed to possess similar microstructures and functional properties as TBCs deposited on reference (forged) substrates for any given YSZ deposition process and feedstock.

Analysis of enthalpy and energy conversion efficiency in high-power inductively coupled plasma

The Near-Space Plasma Electromagnetic Science Experimental Research Apparatus is designed for ground-based simulation of plasma sheath and is capable of providing pure, high-enthalpy, and high-density plasma jets. The high enthalpy implies a high plasma state, which can achieve high Mach equivalent simulation in flight conditions. This paper takes this device as the research object and establishes a multi-physics coupling magnetohydrodynamics model to simulate the heat transfer process under high-power conditions. Through numerical simulation, the distribution rules of plasma temperature and enthalpy value under different power states considering the radiation source are obtained. By combining numerical simulation with experimental verification, the simulated enthalpy and energy conversion efficiency results are compared with experimental data, showing good consistency. The study finds that the enthalpy at the center of the jet outlet is higher, increasing from 5.4 MJ/kg to 9.5 MJ/kg when the high-frequency power increases from 150 kW to 426 kW, with an increase of 4.0 MJ/kg. The overall distribution of plasma jet enthalpy exhibits a central peak, gradually decreasing radially from the center to both sides. Meanwhile, during the axial jet injection process, there is a transition in the radial distribution of temperature and enthalpy, shifting from a saddle-shaped distribution at the coil position to an arch-shaped distribution at the nozzle outlet. In this power range, the energy conversion efficiency of the high-frequency power source ranges from 53% to 30%, with both calculated and measured efficiencies decreasing with increasing power. Additionally, the paper discusses the impact of radiation source terms on the distribution of enthalpy in high-power inductive-coupled plasma. In conclusion, the model proposed in this paper can be used to estimate the outlet enthalpy distribution and energy conversion efficiency of the Near-Space Plasma Electromagnetic Science Experimental Research Apparatus, providing data support for the design, control, and application of the device.

Technical design of an axial injection low-energy carbon beam line

Technical design of an axial injection low-energy carbon beam line

Deposition characteristics and tribological performance of atmospheric plasma sprayed diamond metal matrix composite (DMMC) coatings

Diamond-reinforced metal matrix composites (DMMC) have great potential for wear-resistance applications due to the superior hardness imparted by diamond. Atmospheric plasma spraying involving axial injection of suitable feedstock is a convenient pathway to fabricate DMMC coatings for tribological applications. In this paper, thick DMMC coatings were deposited by plasma spraying Ni–P clad diamond particles under varying spray conditions. It was found that the phase characteristics of DMMC coatings as well as extent of diamond retention and fragmentation were significantly influenced by spray conditions such as, stand-off distance (SOD) and carrier gas flow rate (CGFR). Mechanical characterization (by micro-indentation) on all DMMC coatings developed in this work showed that coatings sprayed with longer SOD and higher CGFR has relatively higher hardness than other two coatings. However, on nanoindentation, the diamond hardness was found overestimated due to effect of diamond roughness on fragmentation. Ball-on-disc wear testing showed excellent tribological properties in all cases, with enhanced wear performance being noted when more diamond is retained in the coating.

Numerical and experimental research on axial injection end-burning hybrid rocket motors with polyethylene fuel

This study investigates the end-burning hybrid rocket motors with polyethylene fuel by the numerical simulation and experiment. Based on computational fluid dynamics, a numerical model is developed. The model is validated by two firing tests in this hybrid rocket motor, which uses oxygen and polyethylene as propellants. The results show that the numerical and experimental data are in good agreement, and the error of the chamber pressure is less than 2.63%. Based on the simulation mode, the blowoff limit of the end-burning hybrid rocket motors is investigated. When the nozzle throat diameter and the inner diameter of grain are large, it is more difficult for the hybrid rocket motor to achieve end-burning mode, i.e., the flame spreading is prevented in the narrow duct. The main reason is that when the nozzle throat and the grain port are large, chamber pressure and oxidizer flow velocity are low. Therefore, the friction velocity considering the pressure and flow velocity is proposed. The critical friction velocity is about 4.054–4.890 m/s in the hybrid rocket motors. When the friction velocity exceeds the critical friction velocity, the combustion mode in hybrid rocket motors changes from the flame spreading mode to the end-burning mode. Moreover, the regression rate formula is obtained by fitting, which shows that the regression rate has a good correlation with combustion chamber pressure. The critical friction velocity and regression rate formula can provide an important reference for end-burning hybrid rocket motors.

An experimental study of steam turbulent jet condensation & upward propagation of thermal plume into sub-cooled water pool

Supersonic steam’s axial injection into water in a cylindrical vessel (1 m high and 24 cm in diameter) was achieved through a nozzle of 6 mm diameter, located at the center of the vessel. Optical examinations were determined through a steam jet to find out condensation rate, which was allied with the steam mass flux (295–672 kg/m2/s) while leaving the nozzle’s exit. The Reynolds number (i.e., 41,000–73,610) has been estimated based on most swollen section of the steam’s jet. Further beyond the condensation zone, the steam, that has been condensed, progresses into a condensed steam plume, which is surrounded by the sub-cooled water. Particle Image Velocimetry (PIV) has been applied to focus region through the mid axis of the heated water plume along a vertical plane of 100 mm × 100 mm cross sections till 400 mm from the nozzle. Central upward averaged velocity profile of the condensed water thermal plume has been evaluated at 295 and 672 kg/m2s, both have hinted the exponential decrease of mean axial velocity when the plume travels vertically upward. The radial velocity distribution of the mean axial velocity across the radial dispersal of the jet, has been obtained as self-preservable and the mean axial velocity attained the Gaussian profile by incorporating appropriate grading of axial distance and mean velocity. Other significant aspect of the current work is to apply the buoyant scaling evolved from the single-phase non-condensing upward thermal plumes to the condensed upward plume through the relations of volume flow, momentum and buoyant being computed from the steam jet operating conditions. The source values of physical dimensionless parameters such as Reynolds number (Reo), Plume Richardson number (Ripo), entrainment coefficient (αo), buoyant vertical scale (Bo) have been evaluated. Based on the radial spread of the velocity profiles along the vertical distance from the condensation region, the dynamics of the thermal and the jet propagation has been highlighted through the evaluation of the dimensionless buoyant parameters along the downstream of the plume. The present experimental measurements obtained for condensed single-phase plume are compared with the experimental results of the non-condensed single-phase thermal plume to signify the vitality of the dimensionless parameters derived from non-condensed plumes.

Effect of water jet area on mitigation of vortex rope in a Francis turbine

The rotating vortex rope (RVR) is normally formed at part load operating conditions, which develops flow instability in the draft tube (DT) cone of a Francis turbine. The detrimental effects of RVR reduce the life and performance of the turbine. The present work mitigates RVR through axial water jet injection in the DT cone. This paper extends the author's previous work on water injection with a 50% reduction in the water jet area through two nozzles with a diameter of 12.7 mm. The effect of area reduction is analyzed by spectral analysis like power spectrum density and spatial harmonic decomposition of the pressure field measured at the wall of the cone. The effect of water jet injection on synchronous and asynchronous pressure pulsations is analyzed at both measurement planes of the cone. The improvement in pressure recovery in the cone and turbine efficiency due to water jet injection is also analyzed. The water is injected at 0.5%–2% of the turbine inlet flow at 22.10° guide vane opening.

Analyzing Microstructural Features, Surface Topography, and Scratch Resistance of Innovative Nano-Composites Coated with High Velocity Air-Fuel Technology

New developments in thermal spraying processes may offer higher-quality alternatives to hard chrome plating and possibilities for hard chrome plating in a range of coating applications. These include spraying with high-velocity air fuel (HVAF) and new spray consumables. The low operating temperatures and accelerated particle velocity of the HVAF process enable investigation and development of a wide range of novel coating materials and applications. The High-velocity Air Fuel Process' quality and efficiency are primarily due to the broad combustion chamber and axial injection of the feedstock through it, as well as the relatively low combustion temperature of an air-fuel mixture and the low gas velocity that provides enough time for the mild heating of the powder particles. The current work discusses the inventive thermal spray procedure used for SAE 1008 carbon steel, a cost-effective substrate material. All of the compositions that were treated have undergone microstructure investigations. A scratch test is conducted in accordance with ASTM guidelines. Assessment of surface morphology clearly demonstrates the relationship between the evaluated parameters. According to the occurrence, scratch methods such as delamination, cracking, plastic deformation, and elastic deformation are highlighted. However, the findings of the scratch test showed that the samples' scratch resistance increased as the coating thickness rose. In comparison to samples with thinner coating, those with thicker coating demonstrated a stronger resistance to scratching. This is explained by the fact that coatings with a higher thickness and density can support the subsurface more effectively and stop cracks from scattering. This can retain the coating's integrity and stop more damage from occurring, improving scratch resistance. Better scratch resistance was displayed by the samples with denser microstructures and smoother surface morphologies. The outcome is greater scratch resistance because a higher density covering can withstand deformation and fracture better than a lower density layer. This is due to the mechanism of deformation and fracture in the coating material. This improvement in scratch resistance can be due to the composites' increased HVAF coating's hardness and adherence. The findings imply that using an HVAF coating to increase the scratch resistance of new nanocomposites may constitute a successful strategy.

Axial water jet injection in a low head Francis turbine at part load

The part load operation of a Francis turbine generally develops a rotating vortex rope (RVR) in the draft tube, generating flow instabilities and pressure pulsations. The present work reports the axial water injection method to mitigate the RVR and its associated pulsations in the draft tube. The runner cone is modified to install a nozzle of three different designs for water jet injection. Water is injected axially at the rate of 0.5% to 2% of the main flow. Spectral analysis is performed to assess the pressure amplitude and dominating frequency affected by the water injection. Spectrogram and spatial harmonic decomposition show a reduction in synchronous and asynchronous pulsation amplitudes. The pressure recovery in the draft tube cone is also improved. The spectral analysis shows that the water injection at 1% and 1.25% is the most effective. The water injection above 1.25% to 2% causes pulsations near the draft tube bend as the water jet bounces back after striking the elbow. A sharp decrease in the Strouhal frequency is observed above 0.5% jet injection. The efficiency of the turbine is also improved by water jet injection.

Flow field characteristics and particle path tracking of a hollow rotating detonation engine with a Laval nozzle

A statistical particle path tracking method is applied to a hollow rotating detonation engine (RDE) with a Laval nozzle, and the flow field characteristics are investigated. The in-house solver BYRFoam based on OpenFOAM is used, and a large-area outflow field at the tail of the combustor and an array of injection holes are implemented. The influence mechanism of the tail nozzle on the internal and external flow fields of the hollow RDE is revealed. The results confirm that the tail nozzle helps suppress the rotating shock wave of the outflow field, which can make the exhaust plume structure more symmetrical. The influencing factors of the flow field of RDE with nozzle are studied. The results show that the farther the equivalence ratio deviates from 1, the closer the normal shock wave is from the nozzle outlet. The paths of representative flow particles are tracked, and the paths and physical properties of flow particles from different injection areas are obtained and compared. The results demonstrate that the overall movement trend of particles along the circumferential direction is opposite to that of the detonation wave, and some particles entering the combustor from the inner hole enter the virtual inner cylinder. The particle paths of hollow RDE without nozzle and RDE with radial injection method are studied. The results show that the particle circumferential deflection angle is smaller for RDE without nozzle and larger for RDE with radial injection method compared to RDE with nozzle and axial injection. A statistical tracking method for a large number of particles is proposed to obtain the flow characteristics of the gas in the combustor. The results confirm that the average circumferential deflection angle and the average residence time and its dispersion degree of the inner hole gas are larger than that of the outer hole gas. Flow particles with smaller initial radial position coordinates produce more curved particle traces. A thermodynamic statistical method for a large number of particles and the concept of a maximum work–heat ratio are used to analyze the macroscopic thermodynamic cycle characteristics of the gas. The results reveal that the maximum net mechanical work and the maximum work–heat ratio of the outer hole particles are larger than those of the inner hole particles. The gas entering the combustor from the outer hole has a greater proportion of chemical energy converted into useful work and a better expansion effect.

A Perspective Review of Passive Techniques Applied to Control the Swirling Flow Instabilities From the Conical Diffuser of Hydraulic Turbines

Abstract This paper represents a welcome synthesis of the results obtained by the authors over more than a decade. The reason why such an approach is perfectly justified is found in the novelty of the control techniques of decelerated swirling flows from the conical diffuser of hydraulic turbines. The results presented in this paper refer strictly to the new passive control techniques of the swirling flows instabilities from the conical diffuser of hydraulic turbines. Although the results of these new techniques have been disseminated in various papers, it is difficult to outline an overview from a collection of articles. In addition, a lot of valuable information about modern experimental and numerical investigations is not found in articles that usually distill only the most significant results. Therefore, the present paper achieves a welcome unitary synthesis, useful to specialists in the field of turbomachine hydrodynamics. The reluctance of the turbine manufacturers on active control techniques that use external/additional energy sources led us to the choice of passive control techniques review, especially the ones developed in the last years. The first part of the paper analyzes the specialized literature that includes a variety of passive solutions for mitigating self-induced instabilities of decelerated swirling flow downstream of hydraulic turbines. Such inherent instabilities manifest intensely at far from optimal operating regimes and represent one of the challenges of modern hydraulic turbines. The mitigation of these instabilities is an open problem, so far there are no unanimously accepted technical solutions implemented on prototype turbines. The second part of the paper includes detailed investigations on axial water injection with flow-feedback, but also more recent approaches using adjustable diaphragm in the conical diffuser.

Microstructure, mechanical and thermal properties of YSZ thermal barrier coatings deposited by axial suspension plasma spraying

Yttrium-stabilized zirconia (YSZ) thermal barrier coatings (TBCs) are indispensable elements of present-day turbine propulsion systems. The ones deposited with atmospheric plasma spraying (APS) are characterized by required low thermal conductivity, but they are unable to survive frequent thermomechanical loading and therefore their application is limited to parts remaining stationary. Expanding capability of TBCs is sought in various areas, but the one realized through modification of most proliferated apparatus used for plasma spraying (PS) (from radial to axial injection) and substituting micrometric powders with the nano-structured suspension needs least changes in the industry established procedures and offers the highest property improvement. The present experiment covered the deposition of ZrO2-8Y2O3 YSZ TBC using both atmospheric and suspension PS processes. They were performed with commercial micrometric and nano-structured YSZ (8% Y2O3) powders. The coatings morphology and microstructure were characterized with 3D profilometry, scanning and transmission electron microscopy (SEM/TEM) methods. Finally, the coating’s hardness and heat conductivity were measured. This complex approach allowed to state that PS of micrometric t’-ZrO2 powder having an admixture of m-ZrO2 phase is capable of only partial improvement in its homogenization. However, the suspension PS process of nano-structured powder eliminated any traces of the monoclinic phase from the coating. The TEM microstructure observations indicated that the suspension PS coating is built by in-flight solidified droplets as well as by the melted ones flattened on arrival. A surface layer of liquefied material on solid droplets increases their adhesion to surface asperities promoting pseudo-columnar growth of the coating. The preservation of monotonic slow increase of thermal conductivity during heating of the suspension PS coating means, that its pseudo-columnar microstructure is better suited to withstand high strains during such treatment.

Azimuthal structures and turbulent transport in Penning discharge

Azimuthal structures in cylindrical Penning discharge are studied with a 2D3V radial–azimuthal PIC/MCC model with the axial magnetic field. The discharge is self-consistently supported by ionization due to the axial injection of electrons. It is shown that the steady-state discharge can be supported in two different regimes with different types of observed azimuthal structures. The transition between the regimes is controlled by the mechanism of the energy input to the discharge. In the first regime (low energy of the injected electrons), with the pronounced m = 1 spoke activity, the power input is dominated by the energy absorption due to the radial current and self-consistent electric field. In the other regime (higher energy of the injected electrons), with prevalent small-scale m > 1 spiral structures, and the lower values of the anomalous transport, the total energy deposited to the discharge is lower and is mostly due to the direct input of the kinetic energy from the axial electron beam. We show that the large (m = 1) spoke and small-scale structures occur as a result of Simon–Hoh and lower hybrid instabilities driven by the electric field, density gradient, and collisions.

Experimental studies on combustion performance of beeswax-paraffin blended solid fuels in a hybrid rocket

The study intends to investigate the physical, chemical and thermal characteristics of paraffin blended fuels to determine their suitability as a solid fuel in a hybrid rocket. Wax fuels are a viable and efficient alternative to conventional rocket fuels, having excellent structural strength and thermal and mechanical properties. By utilizing both axial and swirl injection technique, the combustion performance of paraffin – beeswax blended fuels have been tested with a fabricated cylindrical grain in a laboratory-scale rocket setting along with oxygen. The test outcomes revealed solid fuel compositions of more beeswax content in paraffin wax on an oxygenated gaseous environment with a swirl-flow injection method has the highest average regression rate of 1.649 mm/sec at 181 kg/m2s mass flux. Axially injected oxygen with pure paraffin wax has the lowest value of 0.85 mm/sec at 96 kg/m2s. The regression rate comparisons revealed that oxygen injection by a swirl injector increased the regression rates by 40% for mass fluxes greater than 80 kg/m2s. Compared to other studies, the combustion efficiencies have been obtained in this study are good. Blended fuels can manage and increase combustion efficiencies for axial and swirl flow conditions. Swirl injectors outperform axial injectors for oxygen injection and allow for a higher proportion of Beeswax combined with paraffin. This study exclusively designed and manufactured an axial injector and swirl injector, according to the required dimensions of a lab-scale hybrid rocket's combustion chamber, injector, and exhaust nozzle, and their performances have been evaluated.

Fluid flow of various configurations in a rock-proppant-system

A high rock mass permeability is essential for developing an enhanced geothermal system and commonly achieved through the fracture conductivity. Hydraulic stimulation of fractures in combination with the use of proppants can significantly increase and maintain rock mass permeability. To investigate and quantify the effect of proppants, which are so far not commonly used to enhance deep geothermal reservoirs, on the rock mass hydraulic conductivity we performed various sets of laboratory experiments. We performed long-term creep deformation tests on a stack of rock samples with simultaneous a) fluid flow and b) acidification and fluid flow, in both cases with and without a proppant-filled fracture between the stacked rock samples. A central borehole served as fluid inlet into the lower sample of the stack. Two more boreholes in the lower sample allowed fluid flow. Sample stacks were placed in a Hoek cell at elevated confining pressures to prevent fluid flow along the sidewalls of the cylindrical sample setup. We compared the axial deformation and injection pressures between the experimental setups. The laboratory tests are part of the ZoKrateS Project, which aims at showing the feasibility of enhancing fractured carbonate rock mass by proppant placement for geothermal applications.

Numerical Simulations of Fuel Shape Change and Swirling Flows in Paraffin/Oxygen Hybrid Rocket Engines

The objective of this work is to describe and validate a numerical axisymmetric approach for the simulation of hybrid rocket engines (HREs), based on Reynolds-averaged Navier–Stokes simulations, with sub-models for fluid–surface interaction, radiation, chemistry, and turbulence. Fuel grain consumption is considered on both radial and axial directions and both axial and swirl injection of the oxidizer are simulated. Firing tests of two different paraffin–oxygen hybrid rockets are considered. First, a numerical rebuilding of fuel grain profile, regression rate and pressure for axial-injected HREs is performed, yielding a reasonable agreement with the available experimental data. Then, the same numerical model is applied to swirl-injected HREs and employed to analyze both the flowfield and the regression rate variation with swirl intensity. A validation of the model through the rebuilding of small-scale firing tests is also performed.

Numerical Study on Particle Behavior and Deposition Accuracy in Cold Spray Additive Manufacturing

Cold Spray additive manufacturing (CSAM) is an emerging technique to fabricate freestanding objects by depositing solid-state layers of materials. Thanks to its remarkable deposition rate and maneuverability, it can be tailored to manufacturing intricate geometries in aerospace industries. In comparison to other additive manufacturing techniques, it is the processing speed, solid-state deposition, and the cost that make CSAM unique. In this study, CSAM process was modeled for a system comprised of a high-pressure cold spray gun with axial powder injection. To represent the flow structure around the already built objects and the deposited layers of CSAM, three walls with different profiles are placed on a flat substrate. In this work, the gas-particle behaviors are studied at the vicinity of these non-axisymmetric objects that can be generalized to more complex geometries and the applications of CSAM. The model is 3D and aluminum and copper powders were used for the feedstock. The particles’ conditions upon impact, such as particles’ footprint and normal impact velocities are studied. The numerical results show that the deviation of particles which is caused by the supersonic flow inside the nozzle and the shock waves outside the nozzle defines the accuracy of the deposition. Furthermore, the results manifest the particle’s material and size have a significant influence on the acquired velocities and trajectories of the particles, and consequently on the resolution of the process. It is found that the profile of the deposited layers has some effects on the gas flow near the substrate which plays a role in the dispersion of fine particles.

Numerical modeling of filtration gas combustion in a cylindrical radiation burner for contactless heating of materials

• A new configuration of radiant burner is considered. • The study of the effect of heat loss on the stability of the filtration combustion in a porous medium is carried out • Numerical modelling of the combustion inside a burner with axial fuel supply has shown the possibility of stable operation at high temperature levels. • There is a range of pressure drops at which the process of contactless heating of the material to high temperature levels can be carried out. The filtration gas combustion in a porous cylindrical tube with axial injection of combustible mixture is numerically investigated. This configuration can be potentially used as new type of heater for the contactless heating of materials in industrial processes. The material under treatment is placed inside the cylindrical porous tube and is heating by radiative flux from the cylindrical tube wall. The simulation of the filtration gas combustion in porous burner was carried out within the framework of the two-temperature thermal-diffusion model. Conducted numerical modeling yields qualitative description of the effects of heat removal from the burner on the limits of a stable combustion regime. The data about range of the gas flow rates and the intensity of the heat losses on the burner's inner surface corresponding to the stable combustion were obtained. The temperature distributions in the gas and the porous burner were as well gas flow field were obtained in general case, without addresing to the details of the material processing.