Outlet Temperature Distribution Research Articles

Kriging surrogate model for optimizing outlet temperature distribution in low-emission combustors without dilution holes

Designing advanced combustors that operate at high temperatures and produce little pollution, especially in the absence of primary and dilution holes, is a difficult task that may bring significant challenges. In this regard, this paper introduces a Kriging surrogate model approach to optimize the outlet temperature distribution of the combustor to achieve such advanced low-pollution combustors. Building upon previous research, this study explores the effects of the swirler blade installation angle on the outlet temperature distribution of the combustor without primary or dilution holes. Traditional methods, such as the control variable method using computational fluid dynamics (CFD) for numerical simulation, are limited in application due to the complex coupling of flow, heat transfer, mass transfer, and combustion processes. In contrast, surrogate models, especially the Kriging model, offer a rapid and efficient alternative to extensive CFD simulations that provide accurate predictions and error estimates for the solution of the problem. In summary, this paper details the process of generating sample points through three-dimensional numerical simulations, develops a Kriging surrogate model through Latin hypercube sampling, and optimizes the model to identify the most uniform outlet temperature distribution achievable by adjusting the installation angle of the swirl blade. The optimal design parameters, which are quickly obtained through the Kriging model, showed a significant reduction in the overall temperature distribution function and the radial temperature distribution function by 21% and 27.14%, respectively.

Influence of primary jets on the combustion performance of a rich quench lean combustor: A numerical and experimental investigation

The effect of primary hole jet on the Rich-burn/Quick-mix/Lean-burn (RQL) combustor was studied here by both experimental and numerical analysis approaches, where with a standard k-ε model was applied. To understand the influence of primary hole on the performance of RQL combustor, three primary hole jets configurations with different dimensions of layout were tested. Results from both experimental and numerical studies demonstrate that an increased number of primary holes results in a moderated reduction in the height of the central recirculation zone and the emergence of vortical structures in the quenched zone. Additionally, in the rich fuel region, the flame area decreases with additional primary holes when the equivalence ratio is below 1.0, while it expands when the equivalence ratio exceeds 1.0. The interaction between local recirculation zones is enhanced by additional primary holes, facilitating rapid fuel-air mixing and reducing circumferential ignition time. Notably, a symmetric jet flow scheme with fewer primary holes displays a favorable outlet temperature distribution, characterized by a weighted standard deviation ranging from 0.02 to 0.06, indicating efficient mixing. These comprehensive insights highlight the intricate relationship between primary hole jets and combustor performance.

Numerical simulations on the effect of swirler installation angle on outlet temperature distribution in gas turbine combustors

The higher demand for temperature rises and low-pollution combustion methods make it more problematic to regulate the outlet temperature distribution (OTD) of advanced gas turbines. The present investigation tackles the significant challenge of achieving uniform outlet temperature distribution in advanced low-emission gas turbine combustors devoid of dilution holes, a concern that directly impacts the service life of turbine blades. Differing from the reliance on dilution holes characteristic of conventional combustor designs, this study aims to control the OTD by adjusting the installation angles of the swirler blades. To this end, a thorough numerical analysis is conducted to assess the impact of swirler blade angles on the temperature distribution within the combustor. The findings reveal that an elevated swirl number drives the flame front and regions of high temperature toward the downstream section of the combustor. This downstream shift exhibits the dual effect of potentially improving heat exchange due to enhanced mixing and substantially reducing the outlet temperature distribution factor (OTDF). Quantitatively, the obtained results demonstrate that by fine-tuning the swirler blade angles, a reduction in the OTDF by approximately 33.6 % and a decrease in the radial temperature distribution factor (RTDF) by about 20.4 % can be achieved. These reductions represent a substantial improvement in controlling the temperature field inside the combustor, which is crucial for minimizing the thermal load on turbine blades. In summary, the research provides valuable insights into the design of gas turbine combustors, highlighting an innovative approach to achieving more uniform temperature distributions at the outlet without the exploitation of dilution holes. The results of this scrutiny contribute to extending turbine blade life and improving the overall performance of gas turbine systems, thereby advancing the development of environmentally friendly combustion technologies.

Structure Optimization of Hydrogen‐Fueled Multiple Direct‐Injection Trapped Vortex Combustor Using Response Surface Method

A hydrogen‐fueled multiple direct‐injection trapped vortex combustor is proposed to improve the unstable combustion and reduce NO emission. The effects of bluff‐body depth, bluff‐body height, and bluff‐body angle on the combustion flow characteristics are analyzed. NO emission is used as the main response value, the response surface method (RSM) is adopted to optimize the bluff‐body depth, bluff‐body height, and bluff‐body angle. The results show that the bluff‐body depth, bluff‐body height, and bluff‐body angle have significant effects on the NO emission, with the increase of the three parameters, NO emission first drops and then rises, but the effects on the pressure loss and outlet temperature distribution factor (OTDF) are very small. After optimization by RSM, the optimal bluff‐body parameters are the bluff‐body depth a = 56.5 mm, the bluff‐body height b = 128.9 mm, and the bluff‐body angle α = 77.6°. Under these circumstances, the maximum radial distances of the front concave vortex and the rear concave vortex reach 48 mm and 57 mm, respectively, which enhances the combustion stability. Furthermore, NO emission of 1.64 ppmv in the optimization structure is significantly optimized compared to NO emission of 4.32 ppmv in the original structure.

Performance optimization design of trapped vortex combustion chamber with a sand dune blunt body

In an effort to enhance the performance of the trapped vortex combustion chamber, this paper improved the trapped vortex combustion chamber and proposed a sand dune trapped vortex combustion chamber. Firstly, the effects of different inlet velocities and equivalence ratios on the performance of the two combustion chambers were analyzed. The results showed that under the same operating conditions, the performance of the sand dune trapped vortex combustion chamber was better than that of the trapped vortex combustion chamber. Then, a central composite design (CCD) response surface experimental method was adopted to optimize the structure of the sand dune trapped vortex combustion chamber in detail. The windward angle (α), leeward angle (θ), and rear blunt body height (h) were used as influencing factors. The combustion efficiency (η), pressure loss (δ*), and NOx emissions were used as response variables. Quadratic polynomial regression equations for η, δ*, and NOx emissions were established respectively. Subsequent to this, the expected value function method was employed for multi-objective optimization of the three regression equations. After optimization, compared with the original trapped vortex combustion chamber, the combustion efficiency of the sand dune trapped vortex combustion chamber increased from 87.56 % to 95.41 %, NOx emissions decreased from 747.94 ppm to 386.35 ppm, the outlet temperature distribution factor (OTDF) decreased from 0.21 to 0.07, and field synergy β diminished from 83.11 to 76.60. Although the pressure loss increased from 2.30 % to 3.50 %, this is within an acceptable range.

Spray, flowfield, and combustion characteristics of an external mixing atomizer in a novel cavity-swirler-based combustor

This paper presents an investigation into the performance of two external mixing atomizers designed for a novel cavity-swirler-based combustor, with the aim of achieving high combustion efficiency and uniform outlet temperature distribution. Experimental and numerical analyses were conducted to study the spray characteristics of the atomizers, including the Sauter mean diameter (SMD) and spray angle. The flow field, combustion efficiency, outlet temperature distribution, and pattern factor of the two atomizers were examined under atmospheric pressure and a temperature of 473 K. The results show that the external mixing prefilming atomizer (case-1) exhibits larger SMD and spray angle compared to the external mixing pressure-swirl atomizer (case-2). Furthermore, case-1 demonstrates higher combustion efficiency than case-2 under pilot-only fueling conditions, which is attributed to the larger wake regions achieved by case-1. Interestingly, under pilot-main fueling conditions, case-2 achieves higher combustion efficiency than case-1. This is due to the smaller SMD and longer residence time achieved by case-2. Moreover, case-1 demonstrates more uniform outlet temperature distribution and smaller pattern factor than case-2. This is mainly attributed to the large-scale axial vortex generated by case-2, which significantly improves the mixing intensity between cavity and mainstream.

Effect of flow maldistribution on heat transfer performance and temperature field of plate-fin heat exchangers

Plate-fin heat exchangers (PFHEs) are widely utilized in aviation precoolers, emphasizing not only heat transfer performance but also the outlet temperature distribution, with flow maldistribution impacting both parameters. This study developed a numerical model of crossflow PFHE and a two-dimensional flow distribution model under the condition of flow maldistribution. Experimental validation shows a standard deviation of 6.9%. This investigation delves into the effects of flow distribution offset (ξ) and non-uniformity (ε) on heat transfer performance and outlet temperature distribution. With large temperature differences, variations in fluid properties due to temperature lead to changes in the surface heat transfer coefficient (SHTC). The combined effects of SHTC and temperature difference determine the heat transfer performance. The results indicate optimal heat transfer performance and outlet cross-sectional temperature distribution at ξ= − 0.67 and 1, respectively. For a given ξ, increased non-uniformity deteriorates heat transfer efficiency and outlet cross-sectional temperature distribution. At ε=0.66, relative to the uniform flow, the heat transfer performance and standard deviation of outlet temperature distribution decrease by 10.3% and 45.1%, respectively.

Analysis of vortex combustion flow in a chamber of guide ring coupling with swirl flow

To investigate the impact of different vortex structure on the combustion stability in a chamber, this paper evaluates the performance of a vortex combustion chamber coupled with a swirler and a guide ring. The simulated cases include different guide ring angles of 95°, 105°, 115°, 125° and 135°, in addition to a control case without coupling the guide ring. The distributions of velocity, vorticity, temperature, outlet temperature distribution factor ( OTDF), reaction rate, turbulent kinetic energy ( k), synergy angle ( β), and NO emission are numerically analyzed. Results show that the coupling of the swirler and guide ring changes the vortex structure and significantly influences the chamber performance. The increase of the guide ring angles ( α) enhances the interaction between the swirl flow and the direct jet, which intensifies heat and mass transfer, as well as turbulence. The application of the guide ring induces external entrainment of the jet, leading to the formation of a large central recirculation zone compared to that without a guide ring. With increasing the α from 95° to 135°, both average outlet velocity and tangential velocity ( Vt) at the coaxial line position decrease, while the flame length decreases by 286 mm. And the OTDF variation among all cases is less than 0.065. The β of the central section decreases from 76.18° to 70.17°. Furthermore, combustion chamber without the guide ring exhibits higher temperature and OTDF.

Combustion and emission performance of swirling-flow single trapped vortex combustor

The swirling-flow single trapped vortex combustor (SSTVC) provides a new design approach for aviation engine combustors, showing promising potential for achieving high-temperature rises or low emissions. However, current research on it is limited to demonstrating its feasibility and lacks further investigation into its combustion organization, combustion, and emission characteristics. In this study, experiments are conducted to investigate the flow field, combustion, and emission characteristics of the SSTVC under 5 inlet reference velocities and 3 inlet temperatures. As the inlet reference velocities increase from 9.96 m/s to 14.95 m/s, noticeable changes are observed in the backflow velocity of the cavity, increasing from 33.8 m/s to 48.3 m/s. By combining the flow field structure and flame features, the combustion organization of the SSTVC is summarized. With an increase in the inlet reference velocities, the combustion efficiency remains almost unchanged initially at 95.75% and then increases to 96.55%. The outlet temperature distribution improves, with the pattern factor value decreasing from 0.23 to 0.14. The carbon monoxide emissions initially increased from 94.91 to 99.89 and then decreased to 88.80, the total unburned hydrocarbons decreased from 23.22 to 16.03, and the nitrogen oxide emissions showed no significant change. With an increase in the inlet temperature, all parameters improved, with the combustion efficiency increasing from 93.71% to 96.61%, the pattern factor decreasing from 0.26 to 0.12, and all emission parameters decreasing as well.

Core flow distribution optimization of a natural circulation reactor using genetic algorithm, simulated annealing and characteristic statistic algorithm

Optimization of core flow distribution is a critical issue in nuclear engineering, particularly for natural circulation reactors with limited driving force. By appropriately arranging the resistance at fuel assembly inlets, core flow distribution could be well matched with core power distribution, thereby reducing the non-uniformity of core outlet temperature distribution. This, in turn, could enhance the performance and safety of the reactor. However, the flow distribution optimization throughout the fuel life cycle is a complicated global optimization problem that entails a vast solution space. In this paper, the flow distribution optimization with minimizing the maximum-to-minimum outlet temperature difference as the primary optimization objective, has been carried out incorporating various meta-heuristic algorithms with the core thermal-hydraulic analysis code COBRA, for a 200 MW natural circulation light water reactor. Minimizing the maximum-to-average outlet temperature difference is also chosen as an optimization objective since a smaller maximum outlet temperature is desirable. After the parametric sensitivity analysis of the genetic algorithm, the simulated annealing, and the characteristic algorithm, a set of parameters of each algorithm for the current flow distribution optimization problem has been determined. The results show that different algorithms yield similar resistance schemes under both optimization objectives, and all exhibit satisfying optimization effects, among which simulated annealing converges to the global optimum with significantly less computational costs.

Numerical simulations on effect of cooling hole diameter on the outlet temperature distribution for a gas turbine combustor

The outlet temperature distribution characteristics of a gas turbine combustor are critical to the durability and lifetime of the turbine. Regarding to an advanced high-temperature-rise combustor, the air flow rate for swirling increases while the volume of air used to cool the wall and control the outlet temperature field decreases, causing severe challenges in effectively regulating the outlet temperature field, consequently. In the present work, with a focus on regulating the outlet temperature field under conditions of low cooling and mixed gas volume, numerical simulations of a single-sector centrally-staged combustor are carried out. The effusion cooling structure of multi-inclined cooling holes with 30° inlet angle are used on the liner wall. The impact of liner wall cooling holes with different diameters on the outlet temperature distribution characteristics is analyzed, while the variation in relative areas and distribution shapes of low-temperature regions near the outlet wall and hot streaks are obtained. The results suggest that under a constant inlet mass flow rate, both pattern factor (PF) and radial pattern factor (RPF) of the combustor increase with the increment of cooling hole diameter. Compared to the 0.5 mm hole diameter, when the diameter of each single cooling hole is doubled to 1.0 mm, the PF and RPF increase respectively by 1.14 times and 1.83 times, meanwhile, the combustion efficiency decreases from 99.97% to 97.74%, and the pressure drop reduces from 4.3% to 2.4%. Increasing the diameter of cooling holes enhances the cooling film thickness on the liner wall, resulting in the expansion of low-temperature regions near the outlet wall. Furthermore, in comparison with the smaller diameter, the larger diameter forces the combustion reaction zone to shift toward the outlet, leading to the expansion of hot streaks and a deterioration in the uniformity of the outlet temperature field. The combustor corresponding to the design scheme of multi-inclined cooling holes with 0.5 mm diameter has the most uniform outlet temperature field and the highest combustion efficiency, showing the optimum performance.

Cooling characteristics of dilution holes in can-type combustor of micro gas turbine

For the purpose of studying the effect of structural changes in the dilution zone on the main performance evaluation parameters of the combustor, a can-type combustor of a micro gas turbine containing 16 dilution holes was used as the original structure. Seven optimization cases were designed by adjusting the number of dilution holes and the area of single hole in the range of hole numbers from 8 to 28 while keeping the total area of dilution holes. The main conclusions obtained by the numerical simulation study are as follows. The total flow of the dilution zone decreases with the number of holes reduce but due to the increase of single hole flow with the area, the airflow rigidity is significantly enhanced, so the entire airflow is disturbed more strongly and the dilution effect is strengthened. In general, the total pressure loss of the combustor presented an increasing trend with the decrease in the number of holes, and the pressure loss reaches a minimum value of 3400 Pa when the number of holes is 14. The combustion efficiency decreased as the number of holes increased, when the hole numbers increased to 20, the combustion efficiency dropped abruptly below 95%. The variation tendency of outlet temperature distribution factor (OTDF) is generally consistent with the combustion efficiency, and the minimum OTDF is 0.29 for the number of holes of 28. In summary, compared with the original structure with 16 holes, the OTDF decreases by 7.69%, the NOx concentration decreases by 16.67%, and the combustion efficiency increases by 3.1% when the number of holes is 8. Although the total pressure loss is increased by 8%, it is still within a reasonable range. Therefore the combustor with 8 holes can be considered a better optimized case.

Study on the effect of fuel injection on combustion performance and NOx emission of RQL trapped-vortex combustor

As a combustor that can reduce pollutant emissions, the trapped-vortex combustor can not only reduce the length of the combustor because of its radial classification technology, but also its design concept is inseparable from RQL (Rich burn, Quench, and Lean burn). In this paper, the effects of cavity equivalence ratio and fuel injection cone angle on combustion performance and NOx emission were studied by numerical simulation. It is found that the trapped-vortex combustor achieves RQL combustion mode. The increase of the cavity equivalence ratio results in the non-uniform fuel distribution. However, the fuel injection cone angle in the primary region has little effect on the fuel distribution. With the increase of the cavity equivalence ratio, the combustion efficiency and NOx emission first decrease and then increase, and outlet temperature distribution factor is positively correlated with the cavity equivalence ratio. The difference is that the outlet temperature distribution factor and combustion efficiency show almost the same law with the increase of injection cone angle in the primary region, and the NOx emission decreases, but the reduction is not significant.

Numerical investigation on combustion flow characteristics of a micro gas turbine swirl combustor with different protruded bluff body structures

A micro gas turbine swirl combustor with protruded bluff body is proposed. Compared with no bluff body, the protruded bluff body can significantly improve the combustion performance. When the bluff body height is 40 mm and the length is 30 mm, the average outlet NO emission is reduced by 14.43%, the pressure loss is decreased by 5.96%, and the outlet temperature distribution factor (OTDF) is dropped by 31.93%. The influence of different bluff body lengths (15–30 mm) and heights (10–50 mm) on the combustion flow are numerically analyzed further. The results show that the change of bluff body structure will affect the performance of combustor. In the range of 15–25 mm, with the increase of the bluff body length, the scope of central recirculation zone becomes narrower, velocity near the inlet and pressure loss decrease, the OTDF and field synergy angle β both become larger. When the bluff body length grows from 15 mm to 30 mm, the average outlet NO emission increases by 36.74%. The range of the central recirculation zone is gradually widen, and the average reaction rate grows up with the increase of bluff body height. The synergistic effect becomes better, and the heat transfer capacity is enhanced. When the bluff body height grows from 30 mm to 50 mm, the average outlet NO emission reduces from 35.84 ppm to 25.65 ppm.

Research on the Ignition Process and Flame Stabilization of a Combination of Step and Strut: Experimental and Numerical Study

A combined application of step and strut was put forward to achieve reliable ignition and flame stabilization. In this work, the ignition process and temperature distribution have been tested, and a new reduction approach applied to jet fuel oxidation mechanism was developed to present a flow map via tracking C and H reaction paths, then the minor and major reactions were verified according to relative occurrence probabilities. With the half decrease of mechanism size, bias occurred and was controlled within 1.8%. This reduction method had such characteristics as universality, intuition, and quantification, due to its inherent simplification theory. This simulation of ignition process was always consistent with experimental results, which depicted kernel generation, flamelet breakup and flame propagation. Also, the influence of inlet temperature on outlet temperature and component distribution was performed, the biases of experimental and numerical results were within 5%. Chemical characteristics of Kerosene/air premixed combustible had changed and side reactions occurred to jet fuel above 900 K, which led to a converse effect on flame spreading. The side reactions aggravated the increasing coproducts of CO and CH4, which caused the decrease of volumetric heat production.

Imprecise P-Box Sensitivity Analysis of an Aero-Engine Combustor Performance Simulation Model Considering Correlated Variables

Uncertainties are widely present in the design and simulation of aero-engine combustion systems. Common non-probabilistic convex models are only capable of processing independent or correlated uncertainty variables, while conventional precise probabilistic sensitivity analysis based on ideal conditions also fails due to the presence of uncertainties. Given the above-described problem, an imprecise p-box sensitivity analysis method is proposed in this study in accordance with a multi-dimensional parallelepiped model, comprising independent and correlated variables in a unified framework to effectively address complex hybrid uncertainty problems where the two variables co-exist. The concepts of the correlation angle and correlation coefficient of any two parameters are defined. A multi-dimensional parallelepiped model is built as the uncertainty domain based on the marginal intervals and correlation characteristics of all parameters. The correlated variables in the initial parameter space are converted into independent variables in the affine space by introducing an affine coordinate system. Significant and minor variables are filtered out through imprecise sensitivity analysis using pinching methods based on p-box characterization. The feasibility and accuracy of the method are verified based on the analysis of the numerical example and the outlet temperature distribution factor. As indicated by the results, the coupling between the variables can be significantly characterized using a multi-dimensional parallelepiped model, and a notable difference exists in the sensitivity ranking compared with considering only the independence of the variables, in which input parameters (e.g., inlet and outlet pressure, density, and reference flow rate) are highly sensitive to changes in the outlet temperature distribution factor. Furthermore, the structural parameters of the flame cylinder exert a secondary effect.

Analysis and Optimization of Mixing Performance of the High-Temperature Gas Flow in a Mixing Chamber

A high-temperature gas mixing chamber is a type of mechanical device which has been widely used to obtain airflow at a specific high temperature. When a temperature environment test for aviation equipment is performed, the airflow temperature should exceed 1,000 K and change fast. However, the existing mixing devices cannot meet the requirements for mixing speed and uniformity of temperature environment tests. To solve the problem of low mixing speed and uniformity, this paper proposes an innovative gas mixing chamber design. The proposed design allows cold and hot gases to be injected in directions perpendicular to each other, which increases the collision and heat exchange of gases with different temperatures. In this way, a faster mixing process and a more uniform outlet temperature field are obtained. Moreover, a genetic optimization method is used to improve the performance of a mixing chamber. This method considers temperature distribution, the velocity distribution of the outlet airflow, and the mixing speed. Simulation results show that the proposed method can reduce the mixing time from 4.4 s to 2.3 s, the standard deviation of the outlet temperature distribution from 25.2 to 14.7, and the standard deviation of velocity distribution from 1.3 to 0.36. The experimental results show good consistency with the simulation results, indicating that the simulation and optimization results are reliable, and the mixing performance of the cold and hot gas mixing chamber is significantly improved by the proposed method. The proposed method is important for optimizing the design of similar orifice plates and flow mixing structures.

Program development for mass flowrate distribution optimization in the nuclear power plant

For the compact PWR with cartridge fuel component, the application of flow partition design can significantly flatten the core outlet temperature distribution, improve the outlet subcooling, or reduce the coolant flow, to make more effective use of the coolant and greatly improve the core design performance. However, the three-dimensional power distribution shape of the core will change greatly during its lifetime, and it is difficult to reasonably distribute the flow. In this study, the closed channel core flow partition and water density feedback program is designed by studying the basis of flow partition and designing an optimization method that considers various factors. The optimization search of core flow distribution is carried out to maximize the subcooling degree at the component outlet and flatten the core outlet temperature distribution. In addition, the minimum coolant mass flow and the maximum outlet temperature are estimated under the given core thermal power, three-dimensional distribution and minimum outlet subcooling.

Numerical analysis on hydrogen swirl combustion and flow characteristics of a micro gas turbine combustor with axial air/fuel staged technology

• 1 Axial air staging, axial fuel staging and jet stabilized technology are combined with swirl combustion. • 2 Outlet NO emission decreases from 20.2 ppm to 2.28 ppm as secondary air ratio grows from 0% to 40%. • 3 Fuel staging has a more significant effect on reducing NO emission than air staging. To analyze the effects of the two staging techniques on combustion characteristics and emissions, the influence of different secondary oxygen ratios (0-40%) and secondary fuel ratios (0-10%) on the combustion flow, emission characteristics, field synergy and other parameters of the micro gas turbine combustor are investigated by numerical simulation based on computational fluid dynamics (CFD) method. The realizable k-epsilon model is adopted for turbulence simulation, the combustion model is general finite rate model. The results show that with the increase of secondary oxygen ratio from 0% to 40%, scope of central recirculation zone becomes smaller, outlet velocity grows, OTDF becomes larger and pressure loss rises, the average outlet NO emission decreases from 20.2 ppm to 2.28 ppm, synergy angle β of the central plane becomes larger, and the change mainly occurs in the recirculation zone and the rear of the combustion chamber. As the secondary fuel ratio grows, outlet velocity decreases, pressure loss drops, and the outlet temperature distribution becomes more and more uniform. The synergy between velocity and temperature gradient of the central plane becomes better. When the secondary fuel ratio is 10%, the maximum NO emission on the central axis is 9.27 ppm, which is only 8.51% of the fuel unstaged value. The outlet NO emission does not drop monotonously with more secondary fuel. Fuel staging has a more significant effect on reducing NO emission than air staging.

Effect of a passive control strategy on lean ignition and blowout performance of a gas turbine combustor

In this study, a radial strut is designed in the mainstream channel of a trapped vortex combustor (TVC) to improve the mixing between cavity products and mainstream air. This improves combustion efficiency and uniformity of outlet temperature distribution. However, a certain amount of mainstream flow is entrained into the cavity owing to the blockage of the radial strut; this entrainment deteriorates the ignition and blowout performance. To resolve this problem, a passive control strategy using a vertical jet is proposed to restrain the entrainment of mainstream flow into the cavity. Experimental results indicate that compared with the conventional TVC, the proposed strategy significantly improves the ignition and blowout performance. To gain insight into the experimental results, Reynolds-averaged Navier-Stokes-based simulations with a validation methodology were conducted to simulate the flow field and fuel distribution characteristics of the cavity. The simulation results demonstrate that the passive control strategy can effectively restrain the mainstream air entrained in the cavity. The improved ignition and blowout performance provided by passive control strategy can be attributed to the formation of a desirable flow structure with two vortices and high local fuel equivalence ratio inside the cavity.