Swirl Vanes Research Articles

Strengthened oil-water separation by swirl vane hydrocyclone based on short-circuit flow regulation

Hydrocyclones make it possible to separate oil/water efficiently. Short-circuit flow (SCF), which is a local secondary vortex in hydrocyclones, significantly restricts efficient separation. This study proposes a novel swirl vane hydrocyclone to regulate the trajectory of the SCF to reduce the SCF rate. The separation process in the hydrocyclone field is calculated using computational fluid dynamics coupled with the population balance modeling. The strengthened separation mechanism by the swirl vane is revealed, and the response of structural parameters, such as the angle, numbers, and width of the swirl vane, to the SCF rate and separation efficiency is investigated using the response surface optimization method. The results show that the swirl vane structure prevents the direct generation of SCF, strengthens the outward migration of the heavy-phase droplets, and reduces the probability of droplet breakage. The optimal structural parameters of the swirl vane are a swirl vane angle of 31°, vane number of 6 pcs, and vane width of 2 mm, which has the lowest SCF rate of 1.62 %. The separation efficiency increases by 21.53 %, and the SCF rate decreases by 85.33 % compared with a conventional hydrocyclone. This study provides theoretical guidance and data support for SCF regulation and the development of oil-water separation hydrocyclone.

Influence of the swirl vanes in convergent-divergent nozzle on screech tones and mixing efficiency at subsonic and supersonic jet flow

PurposeThe purpose of this study is to investigate the effect of coaxial swirlers on acoustic emission and reduction of potential core length in jet engines.Design/methodology/approachThe swirlers are introduced in the form of curved vanes with angles varied from 0° to 130°, corresponding to swirl numbers of 0–1.5. These swirlers are fixed in the annular chamber and tested at different nozzle pressure ratios of 2, 4 and 6.FindingsThe study finds that transonic tones exist for the nonswirl jet, creating an unfavorable effect. However, these screech tones are eliminated by introducing a swirl jet at the nozzle exit. Weak swirl shows a greater reduction in noise than strong swirl at subsonic conditions. In addition, the introduction of swirl jets at all pressure ratios significantly reduces jet noise and core length in supersonic conditions, mitigating the noise created by shockwaves and leading to screech tone-free jet mixing.Originality/valueThe paper provides valuable insights into the use of coaxial swirlers for noise reduction and core length reduction in jet engines, particularly in supersonic conditions.

Analysis of stability and internal flow mechanisms in spiral annular flow with different swirlers

Spiral annular flow within ducts is widely utilized in modern industry, with the swirler serving as a critical component in generating such flow patterns. The structure of the swirler significantly influences the generation and stability of the spiral annular flow. This study selected four different swirler structures with outstanding performance from previous research and analyzed their characteristics through visual image processing combined with numerical simulations. By analyzing the amplitude information of the wave fluctuations in the annular swirling flow liquid film under different operating conditions using probability density functions, it was found that the swirler A(Flat-vane swirler) and swirler B(Flat-vane swirler with hub) produced smaller fluctuations in the annular swirling flow liquid film, indicating better stability compared to the swirler C(Arc-vane swirler) and swirler D(Spiral-vane swirler), which exhibited poor performance. Combining the numerical simulation results with the analysis of the internal mechanism of the swirlers, it was discovered that within the swirler A and swirler B, the fluid between the swirler vanes experienced a larger pressure gradient, resulting in phenomena such as “jump” and “pull” under this pressure gradient. This, in turn, contributed to the generation of greater tangential velocity and radial pressure gradient after the fluid exited the swirler. Due to the influence of the swirler structure, the swirler A and swirler B did not completely separate the fluid region into four independent spaces. Instead, in the central connection area of the rear section of the swirler, the gas phase components aggregated earlier, greatly promoting the downstream generation of spiral annular flow. This study analyzed the two-phase flow process and mechanism inside the swirler, filling a gap in previous research and providing important references for the optimization and selection of swirlers.

The Effect of Swirl Number on Lean Blow Out Limits of Lean Direct Injection Combustors

Abstract This is the first study where a single variable sweep of SN is conducted to assess its impact on lean blowout limits (LBO) in a liquid-fueled lean direct injection (LDI) combustor. This study uses a scaled NASA SV-LDI (Swirl Venturi—Lean Direct Injection) hardware and is concerned with the impact of swirl number on the lean blow-out limit of a single-element LDI system at atmospheric pressure. The swirl numbers (SN) were varied from 0.31 to 0.66 using continuously variable active swirl number control system that was developed in-house. It is shown that the minimum operating equivalence ratio is a linearly increasing function of swirl number. While previous literature agrees with the positive slope for this correlation, past work has suggested that the LBO limit is proportional to the swirler vane angle which is shown to be untrue for LDI systems. By actively varying the swirl number, it is proven that LBO is proportional to SN, and it is well known that SN is not proportional to swirler vane angle. Increased SN reduces LBO margin because the better-mixed, high swirl dilutes locally rich pockets of fuel–air mixture in a globally lean flow. In addition to a baseline venturi, which was scaled from NASA's geometry, two other venturis were tested. A low-pressure loss venturi with a large throat diameter showed poor blow-out performance whereas a parabolically profiled venturi improved LBO over the baseline for the same swirl number.

Development of a device for cleaning geothermal fluid from mechanical impurities and dissolved gases

The results of the development of technology and devices for cleaning geothermal fluid from mechanical impurities and dissolved gases are given. The presence of dissolved hydrocarbon gases (methane and heavy hydrocarbons up to 60-90 %) in thermal waters significantly increases their energy potential. However, the presence of dissolved CO2, N2, H2S cause equipment corrosion. Therefore, degassing of thermal waters and cleaning from mechanical impurities allows increasing the reliability of exploiting of geothermal deposits. The technology provides purification of geothermal fluid from particles with a dispersion of 50 to 300 μm and carbonate-calcium mechanical impurities and removal of dissolved gases. The technology is based on the use of hydrodynamic processes of separation of impurities in the turbulent flow of a rotating liquid and gas. The device is equipped with many small-diameter vane swirlers and vortex turbulent washers. High tangential speed in swirlers ensures cleaning of liquid from impurities. Due to the rotation of the flow, the surface of the liquid is dispersed with the formation of a droplet-granular layer, through which the gas to be purified passes. When the pressure of the fluid in the device and swirlers is reduced, dissolved gases (methane, carbon dioxide, hydrogen sulfide) are released from the geothermal fluid. The final purification of the gases from the dripping liquid is carried out using conical vane washers. The device can be used in technologies of geothermal field development. Existing technologies do not solve the problem of protecting geothermal energy systems and devices from carbonate deposits. Testing the models showed that this design provides cleaning from mechanical particles with a size of 100-300 μm and removal of dissolved gases by 95 %. This is enough to ensure the reliability of operation of heat exchange and technological equipment.

Numerical simulation of particle erosion coupled with flue gas desulphurization in the spouted bed

The addition of an axial swirl vane (ASV) and multi-jet distributor plate (MDP) to a conventional spouted bed (CSB) to form an integrated multi-jet swirling spouted bed (IMSSB) combined with internally reinforced components not only optimized its desulphurization efficiency but also exacerbated the erosion of particles on the bed and the internal components. Coupled study of the particle erosion and desulphurization reaction in the flue gas desulphurization process of an IMSSB was carried out based on the CPFD numerical simulation. The results show that: the desulfurization efficiency of IMSSB is increased by 16.6% compared with that of the CSB; in terms of wall erosion, the maximum erosion rate in IMSSB is about four times that of CSB; the erosion condition increases in the vane from the center to the edges; particle erosion is most severe in the fountain area.

Quantification of Mixing Quality Effects on Flashback Limits for H2-Rich Fuel Gases in Lean Premixed Combustion Using Laser-Induced Fluorescence of Acetone

Abstract One of the main challenges arising from hydrogen-rich fuel mixtures is to prevent flame flashback. In typical gas turbines, the fuel is commonly injected through holes in the axial swirler vanes to achieve a high mixing quality. However, this injection method is not perfect and can cause nonhomogeneous mixing regions, so that locally rich fuel clusters can significantly increase flashback propensity. This work aims to establish a link between the local mixing quality of fuel and air and flashback limits obtained experimentally under elevated pressure conditions. The nonreacting experiments have been conducted at an atmospheric mockup test rig and acetone-planar laser-induced fluorescence (PLIF) has quantified the local fuel concentration. Zones of high equivalence ratio are evident close to the center body wall. The near-wall equivalence ratio fields reveal that the critical probability of the local equivalence ratio being greater than the one for perfect premixing is between 20% and 35% for all hydrogen concentrations at the flashback limits observed. A probability of 35% is selected as a critical threshold to derive a correlation between the local and the global equivalence ratio in technical premixing. Even though the correlation is specific to the investigated burner configuration, the presented methodology offers valuable insights into the impact of the local mixing quality on flashback propensity, which can improve flashback prediction models formulated for perfect premixing conditions.

Experimental investigation on the dynamics of buoyancy-induced vortices

Measurements were conducted within the flow field of a buoyancy-induced vortex at laboratory scale with a constant heat flux as input at the ground with swirl vanes set at 30° and 60° to the radial. Time-averaged velocity data were obtained using two-dimensional Particle Image Velocimetry (PIV). The velocity profiles in both cross-sectional and vertical planes were measured at heights of 0.3 m, 0.45 m, and 0.6 m above the ground level, and the time-averaged tangential, radial and vertical velocity components were derived. Two types of the vortex structures are identified based on the core swirl ratio, showing one-cell and two-cell type vortex structures with 30° and 60° swirl vane angles, respectively. Vortex wandering effects have also been investigated, including the centre distributions for different types of flow structures, and its impact on flow strength and vortex core sizes have also been quantified. Detailed turbulence statistics have been measured after removing the wandering effect, which show high level of turbulence intensities within the vortex core.

High Throughflow StreamVane Swirl Distortion Generators: Design and Analysis

Abstract In recent years, the StreamVane technology has developed into a mature and streamlined process that can reproduce swirl distortion for ground-test evaluation of fan and compressor performance and durability. A StreamVane device consists of complex turning vanes that accurately output a distorted secondary velocity field at a defined distance downstream. To further advance the applications and conditions in which these devices operate, a research effort was developed and completed to investigate methods to increase critical Mach numbers. The effort was split into three separate stages: (1) Perform high fidelity computational fluid dynamics (CFD) to identify peak Mach number locations within twin and quad swirl vane pack designs; (2) conduct thorough literature reviews on relevant high throughflow techniques; and (3) design and implement selected techniques to evaluate improvements using the same high-fidelity CFD methods. It was predicted that employing blade lean within high-speed vane junctions increased critical Mach numbers by 6.6%, while blade sweep resulted in a 3.5% increase. The results and conclusions from this effort are presented throughout this paper with a primary focus on comparing Mach numbers and swirl profiles between vane packs with and without high throughflow designs.

The effects of swirler vane configurations on the vortex-mixing interaction and combustion stability in a low-emission combustor

Particle Image Velocimetry (PIV) measurements and Large Eddy Simulation (LES) simulations are conducted for non-reacting and reacting flows to investigate the effects of swirler vane configurations on the vortex-mixing interaction and combustion stability in a low-emission tower-type coaxial-staged combustor (LETCC). Results show that the LES simulation results agree well with the experimental data. The combustor without vane lobes exhibits large mixture fraction bubbles in the inner shear layer (ISL) in non-reacting flow, and shows unstable combustion in reacting flow. Adding lobes to the first main stage swirler vanes eliminates instability factors in both non-reacting flow and reacting flow. Adding lobes to the second main stage swirler vanes suppresses mixture fraction bubbles in the ISL, but forms large areas with low mixture fraction in the outer shear layer (OSL) and outer recirculation zone (ORZ) in non-reacting flow, and induces localized flame extinction and re-ignition within the ORZ in reacting flow, leading to combustion instability.

Control device for improving swirl flame stabilization.

Aiming to improve the stabilization of unstable swirling turbulent premixed flames, an actively controlled swirler and electrical hardware and control software are developed, implemented, and tested in the present study. Stereoscopic particle image velocimetry is performed to calculate the swirl number and study the flame stabilization. A mixture of methane and air with a mean bulk flow velocity of 5.0m/s and a fuel-air equivalence ratio of 0.6 is examined. This test condition, along with an original swirler vane angle of 30°, led to the initial anchoring of an unstable premixed flame at the burner exhaust. The developed actuation mechanism allows for changing the swirler vane angle from 30° to 60° and back to 30°. Increasing the vane angle from 30° to 60° increases the swirl number to relatively large values, which leads to the formation of a recirculation zone, a downward velocity along the burner centerline, and, as a result, the stabilization of an M-shaped flame. After the vane angle is reduced to 30°, the swirl number decreases but remains relatively large compared to its original value. As a result, the recirculation zone is present at the end of the actuation process and a V-shaped flame is stabilized. Improving the stabilization of the swirl flames is made possible because of the control apparatus and the method developed in the present study. The apparatus and technique designed and tested in this study facilitate the development of robust tools for improving the stabilization of swirling premixed flames in gas turbine combustors.

Flow and heat transfer characteristics of an impinging jet augmented with swirl

Jet impingement cooling techniques using conventional nozzles, round jets, and swirling jets are effective heat transfer methods extensively used for various industrial applications. This work proposes a geometrical mechanism that generates augmented swirling and round jets for enhanced heat transfer. The proposed geometry has an axial inlet port and three tangential inlet ports. The total flow is partitioned through these inlet ports using different split ratios (SR), resulting in a single augmented flow comprising swirling and round jets. The impingement heat transfer from a heated flat plate is modelled using steady 3-D RANS based numerical simulations. Also, computations for conventional round jets and swirling jets generated by an in-house developed vane-swirler are performed for the Reynolds number range of 6000–15,000, and for a range of jet-plate distance H = 1.5–4 times the jet diameter D. The optimum conditions for maximum heat transfer for various configurations of jets are presented. From this numerical study, the proposed augmented jet is found to enhance the impingement heat transfer rate at an optimal condition of split ratio (SR-4) and dimensionless jet-plate distance (H/D = 1.5) compared to conventional round jets as well as swirl jets generated by vane swirlers.

Three-dimensional Euler grid approximation method for multi-droplet motions in the steam-water separator

Motions of multi-droplets in steam flow are a common and important phenomenon in various fields such as the environment, chemical industry, and energy. To simulate the motion of multiple droplets, a three-dimensional Euler grid approximation method, which applies to structured and unstructured grids, was proposed. Criteria were established to ensure that the motion of droplets is restricted to the grid nodes without compromising accuracy. The method is capable of updating the information of multiple droplets at each calculation step for all nodes and obtaining distribution information including droplet density and velocity. The multi-droplet motions in the steam separator were simulated and velocity field of multi-droplets showed a symmetrical distribution. The multi-droplet motions process in the swirl vane separator of the steam-water separator was also simulated. The results demonstrated that under the studied operating conditions, the critical droplet radius that can be separated by the steam-water separator was 40 μm. The specific positions of droplet-wall collisions were mainly concentrated on the blades and outer wall of the swirl-vane separator, as well as the inner cylinder. The model may serve as a dependable guide for the optimal solution of separation device structures and simulating various other multi-droplet motion processes.

Assessment of a hydrogen-fueled swirling trapped-vortex combustor using large-eddy simulation

In recent years, the study of hydrogen combustion has gained significant interest due to its exceptional lean blow-out (LBO) performance, high efficiencies, and almost negligible greenhouse gas emissions. The present study combines the advantages of hydrogen combustion with the beneficial characteristics of trapped-vortex combustion (TVC) and swirling flows. Large-eddy simulation (LES) is conducted to evaluate the performance of a swirling trapped-vortex combustor. LES sub-gird terms are described using k-equation subgrid model, while, turbulence-combustion interaction is modelled employing the PaSR (Partially Stirred Reactor) closure with a detailed 23-step chemical reaction mechanism for hydrogen/air. A radial vane swirler is incorporated to supply an annular mainstream and generate a wake region in front of the cavity leading edge to enhance cavity flow entrainment. To evaluate the performance of a hydrogen-fueled TVC under non-swirl and swirling conditions with varying swirl numbers (0.1–0.6), several flow and combustion characteristics are analyzed. These includes temperature distribution, vortical structure, combustion efficiency, NO emission, and flame shape. The results show that a large recirculation zone dominates the cavity for the all swirl numbers resulting in a strong fuel–air mixing and high combustion efficiency. It is demonstrated that the swirling motion effectively mitigates the negative impacts of pressure fluctuations arising from the interaction of combustion with cavity oscillations. A stable flame is observed inside the cavity and in the shear layer at the cavity lip in all cases, merging to form a distinctive C-shaped flame. Increasing the swirl number causes the second part of the flame to move to the wake region before the leading edge, enhancing combustion stability and efficiency. Combustion efficiency exceeds 98.5% for all cases, reaching 99.8% for a swirl number of 0.6. The temperature distribution is nearly uniform inside the cavity, with an improved distribution at the TVC’s outlet for higher swirl numbers. Under non-swirling conditions, the corrected NO concentration is below 5 ppm. Increasing the swirl number escalates the outlet NO emission, nevertheless, a maximum NO concentration of 19 ppm is observed for the swirling cases. Comparing these findings with existing data suggests that the swirling TVC offers advantages over other hydrogen-fired TVC’s.

Modeling of H2/air flame stabilization regime above coaxial dual swirl injectors

The prediction of the stabilization regime of partially premixed H2/air flames above an injector is a main subject of interest for the development of gas turbines powered by hydrogen. The way the flame is stabilized has an impact on NOx emissions, thermal stress on the injector, and combustion stability. A model based on the triple flame speed is revisited and improved to predict flame stabilization using information gathered at cold flow conditions. The model is called TFUP for Triple Flame Upstream Propagation. According to this model, the flame can anchor to the injector only if a zone with a flammable mixture and a sufficiently low local flow velocity exists continuously from the lifted flame to the injector lips. The TFUP model is applied to the case of a H2/air coaxial, dual swirl injector in which both the hydrogen and air streams are swirled. Fuel is injected through the central channel and oxidizer through the external channel. Particle image velocimetry and one dimensional Raman scattering measurements made at strategic locations are used to predict the edge flame speed for which a lifted flame should re-anchor to the injector. These predictions made in isothermal conditions are compared to observations of the flame stabilization regime. The central flow of hydrogen can be mixed with methane and helium and the external flow of air with nitrogen in order to prescribe different theoretical values for the triple flame speed. Predictions agree well with the observations made for all swirl levels conferred to the central fuel stream, fuel injection velocities, hydrogen contents in the fuel mixture injected in the central channel, and nitrogen contents in the oxidizer annular channel tested in the study. Validity limits are also discussed. The methodology presented in this study provides a simple framework to predict flame stabilization on coaxial injectors that can optionally be equipped with swirl vanes.

Thermal performance of gasifier cooking stoves: A systematic literature review.

A systematic literature review was conducted to summarize the overall thermal performance of different gasified cooking stoves from the available literature. For this purpose, availablestudies from the last 14 years (2008 to 2022)were searched using different search strings. After screening, a total of 28 articles were selected for this literature review.Scopus, Google Scholar, and Web of Science databases were used as search strings by applying "Gasifier cooking stove" AND "producer gas cooking stove" AND "thermal performance" keywords. This review uncovers different gasified cooking stoves, cooking fuels, and fabrication materials besides overall thermal performances. The result shows that the overall thermal performance of different gasified cooking stoves was 5.88% to 91% depending on the design and burning fuels. The premixed producer gas burner with a swirl vane stove provided the highest overall thermal performance range, which was 84% to 91%, and the updraft gasified stove provided the lowest performance, which was 5.88% to 8.79%. The result also demonstrates that the wood pellets cooking fuel provided the highest thermal performance and corn straw briquette fuel provided the lowest for gasified cooking stoves. The overall thermal performance of wood pellets was 38.5% and corn straw briquette was 10.86%.

Цилиндрический завихритель потока с удлиненной хордой лопастей

Introduction. Development of vortex apparatuses — devices for swirling flows of liquids and gases — remains an urgent scientific and engineering task. The design of counter vortex damper flow swirling apparatus at the idle water outlet of Belorechenskaya hydroelectric power plant (HPP) is considered. The purpose of the study is to develop an effective counter vortex damper of excess kinetic energy of water flow. Materials and methods. Analytical methods of classical hydro-mechanics are used. The conceptual basis of the research is the fundamental equality of the geometric characteristic of the vortex apparatus by Abramovich (the Abramovich number) to the Chigier-Beer swirl number. Results. It has been found that geometrical characteristic of the cylindrical vane swirler does not depend on radius of exit edges of blades which swirl the flow, but depends on the angle of bevel of blades at this radius. It allows, according to fundamental equality of Abramovich and Chigier-Beer numbers, either to shift the blades along the swirl chamber radius or to perform them with elongated chord, leaving the hydraulic characteristics of the swirl apparatus and swirled flow unchanged, preserving the bevel angle. Lengthening the chord of the vortex apparatus blades increases the reliability and quality of formation of the swirling flow. It has been proved on the base of differential equation describing the flow lines in the cylindrical swirl chamber that chord of a swirl apparatus prolonged blade flowing smoothly around the flow should have a shape of a logarithmic spiral. It is shown that the vortex apparatus made in the form of a vane system of logarithmic spirals forms a flow with potential rotation superimposed on the potential flow. Conclusions. The design of counter vortex damper of flow energy at the outlet of Belorechenskaya HPP with a system of blades in the form of logarithmic spirals has been analyzed. It is offered to recommend the considered design as a typical one for hydraulic units of medium head.

Development of a new premixed burner for biomass gasifier generated low calorific value producer gas for industrial applications

The present paper deals with the design of an efficient premix burner design for low calorific value producer gas as a fuel. The proposed premix and the existing available conventional burner are tested and operated on a 10 kg/h capacity downdraft gasifier with garden waste feed. The premix burner (PB) has dual slits swirl vane for air-fuel mixing along with a bluff body each at an angle of 32° and 45°, designed based on simulation results from numerical simulations. Its performance is compared with a conventional burner (CB). Flame temperature variation at different axial and radial distance for both the burners was studied. Flame temperature variation with λ (Ratio of actual air/fuel by stoichiometric air/fuel) are determined. The average NOx and CO emissions for PB are found to be 55% and 70% lower than the CB under nearly identical conditions. PM10 and PM2.5 particulate matter emissions are 65% lower in PB than CB during a stable flame time (15–120 min). The thermal efficiency for PB mode was 55% and that for CB it was 26%. PB showed a better flame stability, higher flame temperatures, lower emissions and higher thermal efficiency as compared to the CB.

Improved swirl-vane designs: Development of low-pressure-drop tubular dynamic hydrocyclones for pre-dehydration

ABSTRACT Effective pre-dehydration is achieved to stabilize and improve oil production in high water cut oil fields. In order to reduce the pressure loss during the pre-dewatering process, a low-pressure-loss dynamic hydrocyclone (LPDH) was developed. And its swirler vane was designed which can not only drive liquid into circumferential rotational flow but also produce axial pressure. The axial pressure will compensate for the separation process pressure loss. The key parameters that affected the axial pressure were studied, the relative motion between the fluid and the vane was analyzed, and a pre-dehydration LPDH was designed (processing capacity is 1.0 m3/h). The changes in the separation efficiency and axial pressure of the LPDH with the operational and physical parameters were studied by the computational fluid dynamics (CFD) numerical simulation method. The results revealed that the pressure is increased during rotation-starting, and the pressure loss of LPDH was lower than the dynamic and compound hydrocyclones. Notably, low shear stress was generated using the designed vane when the fluid started rotating, and the separation efficiency increased under these conditions. When the speed of rotation of the swirler is 167.5 rad/s, the separation efficiency of the LPDH is greater than 99.8%.

An Investigation into Burner Configuration Effects on Premixed Flame Characteristics for LPG Diluted with CO<sub>2</sub>

Meeting stringent emission regulations, the demand for environmentally friendly fuels is increasing by the day. Alternative fuel must be burned alongside conventional fuel to increase the availability of such clean energy sources. The current experimental study investigates the characteristics of the premixed LPG flames with CO2 dilution in tube swirling and non-swirling burners. The study including testing the effects of equivalence ratios, φ, (0.8, 1, 1.2, & 1.4), CO2 dilution ratios (0%, 5%, 7.5%, & 10%), and aspect ratio of the non-swirling burner (2, 4, 6, 8, & 10). Two swirling burners with swirl number was tested, namely 0.78 & 0.48. The dilution of CO2 has been observed lengthens the flame, particularly at higher equivalence ratios and/or flow rates since there is more than one influence, they all agree on a similar influence on flame height. The flame shortens clearly when using a swirling burner. Besides, when increasing the swirl number, the flame height increases slightly. Also, the swirling burner divided the flame's inner core into segments equal to the number of swirl vanes, and a flower-shaped flame was generated at low flow rates. The burner’s aspect ratio affects flame height insignificantly. Flame stability limits increase for a higher equivalence ratio and it enhances due to CO2 addition. The LPG-CO2/air mixture has an improved reply to beat flame flashback. The addition of CO2 expands the flow rate of stable flame by about 40% and 25% for φ = 1 and 1.2 respectively. Utilizing a swirling burner improves flame stability greatly. The limit between flashback and blowout increased by about three times as a result of using a swirling burner.