Nozzle Inlet Research Articles

Experimental and Numerical Investigation of Spray Scrubber Dust Collection Efficiency

Spray scrubbers are widely used in gas purification applications and allow fulfillment of the demands of air quality norms introduced all over the world. They effectively remove harmful gases like sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter from industrial emissions, reducing their impact on air quality. Moreover, by capturing greenhouse gases such as carbon dioxide (CO2) in certain applications, spray scrubbers contribute to efforts to reduce climate change. Optimization of scrubber internal elements leads to reduced energy usage and lowered water mass flow while maintaining high pollutant removal efficiency. This makes them cost-effective in the long term. The demister is an additional device which is often used in scrubbing systems, and its main task is to prevent the water droplets from escaping through the upper part of the scrubbing chamber. In this article, the pollution (MgO particles) is introduced to the system upstream the scrubber inlet, the working fluid is air under atmospheric pressure, and water droplets are generated by a single nozzle placed inside the scrubber. Before the experimental part, a preliminary numerical analysis of gas velocity inside scrubber is performed and expectations of particle behavior are indicated. Then, the authors present the spray scrubber laboratory stand designed by them and carry out experimental research on it. Each element of the test stand is described in the article including the self-designed fluidizer, which effectively mixes MgO powder with air. The authors investigate the effect of their innovative construction of demister on separation efficiency and compare the results to the case without demister. The impact of water mass flow rate generated by the nozzle and gas inlet velocity on separation efficiency is presented for several investigated cases. The results show that demisters significantly improve the separation efficiency at lower water mass flow rates and successfully prevent water droplets from reaching the scrubber outlet. The measured separation efficiency was in the range of 80% for lower water mass flow rates up to 97% for the highest water flows.

Evaluation of water distribution and uniformity of sprinkler irrigation based on harmonic analysis and finite element method

A model that describes the water distribution of a single fixed spray plate sprinkler (FSPS) based on the harmonic analysis was proposed. The relationship between the pressure head, nozzle diameter, mean sprinkler irrigation depth, and amplitude was established. An analytical model for evaluating the sprinkler irrigation uniformity coefficient of a multi-sprinkler combination was developed by introducing a weighting coefficient. In conjunction with the sprinkler irrigation system's finite element hydraulic calculation model, the impact of the pipe diameter, sprinkler number, and sprinkler spacing on system energy loss, pressure head, and sprinkler irrigation system uniformity was assessed. The results demonstrated that under varying pressures and nozzle diameters, the Camargo and Sentelhas coefficient (c) between the measured and fitted mean value of the sprinkler irrigation depth of a single FSPS was greater than 0.99, while the c between the measured and fitted amplitude value was approximately 0.93. Under different combinations of nozzle, pressure head, and sprinkler spacings, the measured, derived, and calculated values of 54 sprinkler irrigation uniformity combinations were basically consistent. The uniformity of the combined FSPS under a linear-move sprinkler system was significantly affected by nozzle diameter, pipe diameter, sprinkler spacing, and inlet pressure head at 0.01 level. The number of sprinklers also had a significant impact at 0.05 level. The findings of this study could serve as a theoretical foundation for the proper design of linear-move sprinkler irrigation systems.

Numerical simulation of radial duel-stage nozzle vortex cooling at the leading edge of a gas turbine blade

Thermal failure is one of the major challenges faced by the leading edge of gas turbines, which significantly affects the improvement of their efficiency. The vortex cooling technique has become a promising solution to address this issue. Radial duel-stage nozzle vortex cooling (RDNVC) model, featured with a vortex tube and two sets of nozzles, is proposed based on the radial single-stage nozzle vortex cooling (RSNVC) configuration. This novel structure aims to intensify turbulence within the cooling fluid at the nozzle inlets, thereby improving heat transfer at the leading edge. The model improves turbulence in the cooling fluid, promoting better heat transfer at the leading edge. Numerical simulations with the SST k-ω turbulence model were performed to analyze heat transfer and flow characteristics at varying Reynolds numbers (Re). The results show that the non-uniform inlet velocity in RDNVC increases turbulence and vorticity inside the vortex tube, leading to improved heat transfer. At the same cooling airflow rate, RDNVC increased the global average Nusselt number by 23.56% compared to RSNVC. Nu increases with Re. Among the three models, RDNVC(6–2) (nozzle heights of 6 mm and 2 mm) showed the best thermal performance, followed by RDNVC(2–6), while RSNVC had the lowest thermal performance. For the same pressure drop, RDNVC(2–6) achieved an 8.42% improvement in heat transfer efficiency over RSNVC. Based on Re and geometry parameters, the empirical correlation for the global average Nusselt number of RDNVC is also proposed.

Optimization method for nozzle control of governing turbine

The compressed air energy storage (CAES) system necessitates rapid and precise adjustment of turbine operational states to align with fluctuating system loads during the energy release process. As the air storage pressure continuously declines, the adoption of an appropriate air distribution method becomes imperative to enhance turbine performance. This study innovatively investigates the coupled optimal method of nozzle control (NC) and relative stator installation angle (RSIA) to achieve maximum specific work under certain output work conditions, initially proposing the optimal method as a strong candidate for engineering applications. The stator channel has undergone redesign to allow adjustment of the stator installation angle. It is investigated to obtain the response surface model of specific work and output work with base pressure (BP), regulated pressure, inlet nozzle number, and RSIA as independent variables, and the maximum specific work as the optimization objective. The results indicate that, compared with the original NC method at rated output work, the optimized operation markedly elevates the specific work by a maximum of 6.1 % and an average of 3.4 %. Furthermore, the majority of losses within the turbine are attributed to entropy production rate by turbulent dissipation, accounting for up to 88.7 % of the total losses. The optimal method satisfies the output work requirement by adjusting the inlet nozzle number and RSIA without throttling the inlet nozzles under different BP conditions. This is achieved by adopting the 3-nozzle inlet method under high BP and the 4-nozzle inlet method under relatively lower BP conditions. The present study offers theoretical support for the optimal design and operation control of NC turbines, which has broad prospective applications in the optimized air distribution regulation of CAES systems.

Simulation-Based Design for Inlet Nozzle of Vortex Tube to Enhance Energy Separation Effect

The vortex tube, also known as the Ranque–Hilsch vortex tube, is a mechanical device that separates compressed gas into hot and cold streams. It offers a reliable and cost-effective solution to a wide range of cooling applications, as it operates without moving parts, electricity, or refrigerants. Research on vortex tubes has primarily focused on understanding the mechanisms of energy separation and optimizing cooling performance by altering geometric operational parameters. In this study, a Computation Fluid Dynamics (CFD) analysis was conducted to enhance the prediction of energy separation performance and improve the overall energy efficiency of the vortex tube. First, the geometry of the experimental device was modeled to closely match its actual shape, unlike the simplified geometries commonly used in previous CFD studies. Simulations were then carried out with variation in grid systems and turbulence models, and the results demonstrated improved agreement with experimental data compared to those reported in previous studies. Finally, simulations with a modified shape of the inlet nozzle shape were performed, revealing that the energy separation effect of the vortex tube could be enhanced by approximately 15% with an increased inlet expansion ratio (ϵ) while maintaining a constant nozzle length.

Effect of cyclone on the CO2 separation characteristics of a vortex tube

Carbon capture and storage has been suggested as a strategy for combating climate change. Cryogenic carbon capture has been demonstrated to effectively capture CO2 from the exhaust gas of fossil fuel combustion at the plant level, but it comes at the cost of high energy consumption. Vortex tubes are devices that mechanically separate compressed incoming gas into hot and cold streams that can potentially facilitate cryogenic carbon capture. In this study, a vortex tube was applied to separating CO2 from an air/CO2 mixture. The design of the vortex tube was modified by the addition of a specially designed vortex generator and a cyclone cone to the cold outlet. The effects of gravity, the inlet nozzle size, and shape of the cyclone cone were evaluated. The results showed that a vertical setup incorporating the effect of gravity improved the CO2 separation performance. Increasing the inlet nozzle velocity increased the CO2 concentration at the cold outlet. The cyclone cone was more effective at angles of 10° and 20° than at angles of 30° or greater. Finally, the effectiveness of the cyclone cone was more pronounced with higher CO2 concentrations at the inlet.

Optimization of a cyclone combustor in a flameless combustion using producer gas

Flameless combustion of producer gas offers significant environmental and efficiency advantages, but its implementation requires careful optimization of both the combustor design and operating conditions. This article is aimed to design a combustion chamber utilizing producer gas for achieving flameless combustion using SOLID-WORKS, computational fluid dynamics (CFD) ANSYS-FLUENT simulation and Design of Experiment (DOE) from Minitab software. The design varied inlet nozzle diameters from 20 to 50 mm and combustor heights from 500 to 800 mm. Computational fluid dynamics (CFD) simulations is utilized to explore the impact of altering chamber height and inlet diameter in order to achieve efficiency in flameless combustion. The producer gas composition and simulation parameters were based on prior studies. The evaluation is focused on CO, NOx emissions and the Damköhler number, and using Design of Experiment (DOE) methodology for optimization. Results showed that chamber height and inlet diameter had limited effects on combustion and CO emission. Therefore, increasing chamber height raised NOx emissions due to prolonged fuel exposure to high temperatures, while varying inlet nozzle diameter has no effect on Damköhler number, but chamber’s height does. Finally, Minitab optimization suggested a chamber with 30 mm inlet nozzle diameter and 600 mm height for desirable flameless combustion, and operating on an equivalence ratio of φ=0.7 which resulted in the lowest CO and NOx emissions, with values of 71.5 ppm and 5.05 ppm, respectively.

Simulation study on the cavitation flow characteristics of liquid ammonia in the nozzle under high-pressure injection conditions

In this study, a non-isothermal compressible cavitating flow simulation model for liquid ammonia in high-pressure injector, accounting for the phase change properties, was established. The model was validated using experimental data from existing literature. The cavitation phase change process of liquid ammonia within the injector nozzle was investigated, and the differences in cavitation distribution between ammonia and diesel were explored. The results indicate that with increasing injection pressure, the vapor volume fraction of ammonia increases linearly, while that of diesel fuel shows a rapid initial rise followed by a decelerating trend. In terms of flow coefficient, ammonia is lower than diesel, though the two values converge at higher injection pressures. Under low injection pressure, the heat absorbed by the cavitation phase change of ammonia exceeded the heat generated by the high-speed friction of ammonia flow against the nozzle wall, leading to a temperature drop at the nozzle inlet. Conversely, at high injection pressure, the temperature of ammonia on the nozzle wall increases by more than 20 K, resulting in a rapid rise in saturated vapor pressure and significantly intensifying the cavitation effect. Compared to ammonia, diesel experienced a higher temperature rise within the nozzle but exhibited smaller variations in saturated vapor pressure, making the temperature effect on cavitation less pronounced. Diesel’s higher density and viscosity resulted in lower flow velocities compared to ammonia, leading to more developed cavitation in the lower wall region of the nozzle and creating a higher pressure region on the upper wall of the nozzle, which was more distant from the nozzle inlet and inhibited cavitation development there. The research results provide theoretical support for the design of liquid ammonia injectors.

Experimental comparison of cycle modifications and ejector control methods using variable geometry and CO2 pump in a multi-evaporator transcritical CO2 refrigeration system

To reduce the direct global warming impact of refrigerants in HVAC&R applications, low-global warming potential (GWP) refrigerants, including natural refrigerants, have been extensively investigated as alternatives to hydrofluorocarbon (HFC) refrigerants. Among the natural refrigerants, Carbon Dioxide (CO2) offers several advantages, such as excellent transport and thermo-physical properties, being neither toxic nor flammable, and having a low price and high availability around the world. However, the high critical pressure and low critical temperature of CO2 often lead to transcritical operation, resulting in lower efficiency due to the additional compressor power necessary to achieve transcritical operation relative to subcritical HFC cycles. Therefore, a number of cycle modifications are used to enhance the coefficient of performance (COP) of transcritical CO2 cycles to meet or surpass those of HFC cycles. This paper provides a systematic experimental investigation of four such cycle architectures by employing the same multi-stage, two-evaporator CO2 refrigeration cycle test stand, 3 of these configurations in transcritical and 1 in subcritical conditions. The four cycles architectures included intercooling, open economization, an internal heat exchanger and two different ejector control approaches. Specifically, a variable-diameter motive nozzle and a variable-speed liquid CO2 pump located directly upstream of the ejector motive nozzle inlet were analyzed. Based on the experimental data, the maximum COP improvements are 4.64 % and 9.47 % when the ejector and the internal heat exchanger are used, respectively. The CO2 pump, once successfully stabilized, can control the ejector, increase its efficiency by up to 15 % and increase the cooling capacity to a maximum of 6.2 %. Nevertheless, a reduction in COP is measured when the pump is in use; however, unlike the other three different configurations, it was only analyzed under subcritical conditions.

Influence of the position of an Internal Heat Exchanger on the performance of a Dual-Evaporator Ejector Refrigeration System

Abstract Energy and exergy analyses were performed to assess the effect of IHX position on the performance characteristics of a dual-evaporator refrigeration system using an ejector as expansion device. Three positions were tested. The first one generates a superheating at the suction of the compressor, the second generates a superheating of the secondary fluid at the inlet of the ejector and the third generates a superheating of the primary fluid at the inlet of the motive nozzle. The results of the simulation show that it is the second position which leads to the best increases in performance characteristics of the refrigeration system. With improvements in COP, Volumetric Cooling Capacity, exergy efficiency and refrigeration cooling capacity of 9.38%, 9.58%, 5.18% and 19.12%, respectively R1234yf is the best fluid. However, the use of IHX is not recommended for R717, especially in position 1. The results also show that the contribution of IHX to increasing system performance is greater the higher the degree of sub-cooling and the lower the IHX effectiveness. It was also noted that system performance increases with condensing and refrigeration temperatures and decreases with freezing temperature.

Flow-field analysis and performance assessment of rotating detonation engines under different number of discrete inlet nozzles

This study explores in depth rotating detonation engines (RDEs) fueled by premixed stoichiometric hydrogen/air mixtures through two-dimensional numerical simulations including a detailed chemical kinetic mechanism. To model the spatial reactant non-uniformities observed in practical RDE combustors, the referred simulations incorporate different numbers of discrete inlet nozzles. The primary focus here is to analyze the influence of reactant non-uniformities on detonation combustion dynamics in RDEs. By systematically varying the number of reactant injection nozzles (from 15 to 240), while maintaining a constant total injection area, the study delves into how this variation influences the behavior of rotating detonation waves (RDWs) and the associated overall flow field structure. The numerical results obtained here reveal significant effects of the number of inlets employed on both RDE stability (self-sustaining detonation wave) and performance. RDE configurations with a lower number of inlets exhibit a detonation front with chaotic behavior (pressure oscillations) due to an increased amount of unburned gas ahead of the detonation wave. This chaotic behavior can lead to the flame extinguishing or decreasing in intensity, ultimately diminishing the engine's overall performance. Conversely, RDE configurations with a higher number of inlets feature smoother detonation propagations without chaotic transients, leading to more stable and reliable performance metrics. This study uses high-fidelity numerical techniques such as adaptive mesh refinement (AMR) and the PeleC compressible reacting flow solver. This comprehensive approach enables a thorough evaluation of critical RDE characteristics including detonation velocity, fuel mass flow rate, impulse, thrust, and reverse pressure waves under varying reactant injection conditions. The insights derived from the numerical simulations carried out here enhance the understanding of the fundamental processes governing the performance of RDE concepts.

Effluent nozzles in reverse-vortex-stabilized microwave CO2 plasmas for improved energy efficiency

Energy efficiency and conversion in a reverse-vortex microwave CO2 plasma are enhanced by optimizing the thermal trajectories using a converging diverging nozzle in subsonic flows. The nozzle mixes cold, unconverted gas at the edge of the flow with hot, active gas in the middle of the flow. Temperature measurements are taken of the quartz tube as well as just above the nozzle inlet and directly after the nozzle and presented to elucidate differences in performance. Measurements show significant improvements in conversion and energy efficiency, especially at pressures close to atmospheric pressure (500 – 900 mbar). In addition an improvement in plasma stability when adding a converging diverging nozzle. Thermal measurements also point towards a shift in energy loss mechanisms when changing flow configurations.

Jet centrifugal pump internal flow numerical simulation and structural optimization

Abstract Jet centrifugal pump is essential equipment in multiple systems such as agricultural irrigation and energy production. This paper investigates the internal flow characteristics of jet centrifugal pumps at different flow rates and the cavitation behavior under high flow conditions by numerical simulation methods. Additionally, two performance optimization strategies are proposed based on simulation results. The findings indicate that high-velocity regions and low-pressure zones exist within the nozzle. As flow rate increases, the outlet velocity of the nozzle gradually decreases, and large areas of low pressure are observed near the inlet of the impeller. Cavitation occurs to varying degrees at flow rates of 4.056 m3/h and 3.840 m3/h. The turbulent kinetic energy contours for these conditions reveal uneven distribution within the jet nozzle, with higher values near the jet mixing layer, inner wall of the jet nozzle and impeller inlet. Structural optimization using hemispherical bolts significantly reduces the turbulent kinetic energy around the bolts, resulting in an increase in head ranging from 1.68% to 6.70% across various flow rates. Shortening the clearance between the impeller and the rear cover reduces energy losses, leading to an increase in head ranging from 2.72% to 5.86%.

MATHEMATICAL MODEL OF NICKEL-GRAPHENE COMPOSITE INKS FOR JETTING PROPERTIES IN INKJET PRINTING

The droplet formation process in inkjet printing is studied numerically and verified through a simulation model. The droplet formation process decides the printing quality of the coating, and a mathematical model is developed to understand the complete process from droplet formation to detachment. The Navier-Stokes equation is used to mathematically derive the droplet radius (rnumerical). COMSOL multiphysics is used for simulation and the radius (rsimulation) is calculated from the droplet mass. The rnumerical and rsimulation are compared for inks containing nickel, graphene, and nickel-graphene composite ink it is observed that the composite ink radiuses have the lowest difference (rsimulation - rnumerical =0.085µm). A droplet is formed at 1.47mm from the nozzle inlet, for nickel-graphene ink, and after 1.5mm for other pristine inks. The results are verified through Z number, velocity profile, and droplet mass. The droplet formation observed from the velocity profile is earliest at 120µs. It is seen that a stable droplet is generated at 100µs for nickel-graphene ink and at 200 µs for individual inks.

Numerical investigation of air entrainment and outlet temperature characteristics of an infrared suppression device with obstacles

Infrared suppression devices (IRS) are crucial for stealth capabilities of modern naval ships and fighter jets. This study numerically investigates the air entrainment and outlet temperature characteristics of an IRS device with conical and spherical obstacles using finite volume method, to solve continuity, momentum, energy, and eddy viscosity-based k-ε equations. We vary Reynolds number (Ren), blockage volume ratio (Vob/Vmf), funnel-overlap height (Hov/Dn), and the nozzle inlet temperature (Tin/Tinf) within the ranges of 3.23×105 to 1.914×106, 0 to 0.106, 0 to 0.653, and 1.243 to 2.577, respectively, to analyze their impacts on enhancement in air entrainment and attenuation in outlet temperature. We observed that the dimensional air entrainment rate monotonously increases with the Reynolds number, and the obstacles further improve air ingestion. The conical obstacle entrains 28.96% more air than the spherical obstacle at a same Reynolds number (Ren=3.225×105) and blockage ratio. The blockage ratio positively impacts on the air ingress; and the maximum air ingestion occurs at a blockage ratio of 0.0266. An IRS with the higher positive overlap-height of funnels promotes air ingress to suppress the outlet temperature. Within the studied overlap height range (0–0.49), air ingress is enhanced by 50% and 85.9%, respectively at Ren=3.225×105 and 1.914×106. At Ren=1.914×106, the IRS exhibits 1.67 times more air entrainment rate at Tin/Tinf=1.91 than at Tin/Tinf=1.2438.

Sensitivity Analysis of Injection Mass Flow to the Inlet Orifice Radius of a GDI Injector Nozzle

It is more difficult to accurately control the cycle fuel mass of a gasoline engine as the injection pressure increases, and the difference in the injection mass flow will become intense due to the machining error of GDI injector structural parameters. In order to guarantee the uniform cycle fuel mass of the GDI injector, this paper investigates the effect of the inlet orifice on the injection mass flow and the sensitivity of inner-flow characteristics in the GDI injector nozzle to the inlet orifice radius by the single factor analysis method. The results show that the local resistance of the injector nozzle will decrease and the discharge coefficient will rise due to the increase in the inlet orifice radius; the sensitivity of cycle fuel mass to the inlet orifice radius is most strong at r = 0.02 mm, and its accuracy should be improved when grinding the chamfer of the nozzle inlet; the sensitivity coefficient of the inlet orifice radius will rise up, and the machining accuracy of the inlet orifice radius should be improved as there is an increase in injection pressure.

Quantitative analysis of energy transfer and separation in vortex tubes: Factors and empirical insights

As a device with a simple structure for energy separation, the low efficiency of the vortex tube is the primary obstacle hindering its widespread application. No existing energy separation theory has gained wide acceptance due to inconsistencies with actual processes. Therefore, drawing on prior studies concerning the flow field, the formation process of flow distribution is presented. Then a quantitative analysis of the energy transfer and separation processes in vortex tubes driven by velocity gradient, temperature gradient, and pressure gradient is proposed. The viscous shear work, heat transfer, and turbulent heat transfer processes were analyzed separately. It was found that the main factors of vortex tube energy separation originated from the expansion of the inlet nozzle and the turbulent heat transfer process. At the same time, the viscous shear work and heat transfer processes also have a specific effect on the energy separation, in which the heat transfer process suppressed the energy separation effect of the vortex tube. In addition, its empirical results indicate that interactions among the turbulent heat transfer process, frictional dissipation, angular momentum conservation, and heat transfer should be considered in further studies.

Assessment of nozzle performance in high-viscosity oil spray system for rectangular copper conductors

This article presents a detailed examination of the performance characteristics of a high-viscosity spray oil cooling system, utilizing various commercial nozzles. These include one spiral hollow cone nozzle, three full cone nozzles, and three flat fan nozzles, all of which were subjected to experimental investigation. Parameters such as temperature, temperature uniformity, injection pressure, spray coverage, spray patterns, spray angles, spray capacitance, heat transfer coefficient, and spray power consumption were assessed to gauge the system's effectiveness. To conduct these experiments, a dedicated test bench was constructed, and a range of commercial nozzles with different spray patterns (full cone, hollow cone, and flat fan) and spray angles (narrow, medium, and wide) were selected. Through a series of experiments, the influence of various nozzle input parameters was scrutinized, with a focus on heat transfer capabilities, temperature uniformity, and cooling efficiency. The results revealed that increasing the nozzle's inlet pressure significantly improves its performance. Moreover, nozzles with medium to wide spray angles demonstrated the best cooling performance, particularly flat fan nozzles in this category. Based on these findings, the article offers recommendations to enhance temperature regulation and cooling efficiency for improved overall system performance.

DEPENDENCE OF MICROHARDNESS OF ASD-1 COATINGS ON COLD SPRAYING PROCESS PARAMETERS

Purpose. To investigate the effect of the main parameters of the cold spraying process, particularly the temperature and pressure of the gas at the nozzle inlet and stand-off distance, on the microhardness of the ASD-1 aluminum coating. Research methods. The planning and conducting of experimental research were carried out using the design of experiment methodology and regression analysis. The analysis of the obtained results of the experiments was carried out in the software package for statistical data Stat-Ease 360. The research of the microhardness of the sprayed coatings was carried out following GOST 9450-76 “Measurements microhardness by diamond instruments indentation@ using a LECO AMH5 micro-Vickers hardness tester on the prepared cross-section of samples with coatings. Results. Three-dimensional (response surfaces) and contour graphs of the dependence of the microhardness of coatings deposited by the cold spraying method from ASD-1 powder on the main process parameters - the temperature and pressure of the gas at the nozzle inlet and stand-off distance in a wide range of values - were constructed. According to the results, it was established that the gas temperature and the spraying distance have the most significant influence on the microhardness of the coatings. The relationship between the investigated parameters of spraying with the temperature and velocity characteristics of the powder particles and their effect on the microhardness is described. Scientific novelty. The complex effect of the main parameters of the cold spraying process, particularly the temperature and gas pressure at the nozzle inlet and the stand-off distance, on the microhardness of ASD-1 aluminum coatings in a wide range of values, was investigated. Practical value. The obtained dependences of coating microhardness on process parameters can be used in developing scientifically-based recommendations and technological processes of deposition of protective and restorative coatings by cold spraying, particularly on parts of aircraft engines.

Numerical investigation of hydrogen ignition induced by unsteady flow phenomena

The purpose of the present study is to evaluate the possibility of using a gas dynamic heater as an igniter of the combustible gas mixtures. The impacts of some operating and geometrical parameters on average temperature of the gas dynamic heater are investigated by numerical simulation of axisymmetric turbulent flow in the resonance tube. The operating gas of the heater is air which is completely decoupled from the ignition chamber. The combustible mixtures under consideration is stoichiometric hydrogen-oxygen at atmospheric pressure, in which the ignition is studied solving the governing equations for one dimensional reacting flow using detailed chemistry. The finite volume method is used in the presently developed flow solver for numerical simulations. The results show that despite highly fluctuating temperature of the end wall of the resonance tube as a hot surface, it can provide proper condition for gas mixture ignition in the chamber, by adjusting an inlet pressure and geometry of the gas dynamic heater. The end wall average temperature depends on the nozzle inlet pressure and convergence angle of the resonance tube, and the results demonstrate that the characteristics of temperature time history of repeating cycles are so effective on ignition process.