Swirl Vanes Research Articles

ACOUSTİC SİGNATURE OF TWO CUTTERS AND FOUR CUTTERS EV SWİRL STABİLİZED GASEOUS BURNERS

ABSTRACTToday’s gas turbine technology is established in a wide range of applications, including (i) the production of electrical power, (ii) thrust generation in turbojets and (iii) driving large size pumps and compressors. The greatest advantages of gas turbines against other prime mover systems e.g. steam turbine systems and piston engine systems, lie in its higher specific power, compact design and low initial costs based on power output.A major problem in gas turbine combustors is combustion instabilities which may cause many undesirable effects including; (a) increased noise levels, (b) oscillating thrust, (c) mechanical vibration that may lead to serious damage and even total loss of the system. These instabilities are characterized by large oscillations of the flow parameters, which in many circumstances may result in the inability of the combustion process to sustain these large oscillations; leading to partial or total flame blow-off. These combustion oscillations could, however be desirable as in pulsed combustors; as it enhance combustion intensity, increase thermal efficiency and reduce the emission of pollutants like NOx, CO and soot. In light of the above mentioned concepts, the present study is directed towards extending the previous studies on the recently introduced turbojet EV burner having two-circumferential swirling entry air passages by a four-circumferential swirling air entries configuration.This burner design concept appears to offer many advantages, including: The replacement of the traditional fixed vane swirler by circumferential swirling air passages; and hence not only minimizes blockage and allows prior premixing of fuel and air within the conically shaped entry section to the combustor but also eliminates possible risk in case of swirler blade damage.The study is an experimental investigations of the acoustic signature of a newly designed 4-slot EV burner. All the results are to be compared with those obtained by the previously developed 2-slot configuration. This allows the identification of the merits and/or drawbacks of both designs.

Experimental investigation on flame appearance and emission characteristics of LPG inverse diffusion flame with swirl

The flame appearance and emission characteristics of a LPG inverse diffusion flame (IDF) are studied experimentally in a coaxial burner. Flame length, CO and NOx emissions are examined at different equivalence ratio and swirler vane angle. The flame length of non-swirling IDFs steadily increases with increase in the fuel jet velocity. A reduced flame length is observed with the increasing air jet velocity. The IDFs with swirl are wider, shorter and stable compared to the IDFs without swirl due to the generation of internal recirculation zone (IRZ). The soot formation in the IDF is qualitatively estimated with the soot free length fraction (SFLF). The SFLF increases with an increased air jet velocity due to the effective entrainment of the fuel, which leads to an improved premixing of the fuel and air to produce an elongated blue zone of the IDF. The IDFs with swirl are wider, shorter and stable compared to the IDFs without swirl. IDFs with the 30° swirler have comparable characteristics of the CO and NOx emission with that of non-swirling IDFs. The adequate entrainment and the swirl effect for vane angle of 30° produce favourable environment corresponding to low CO and NOx emission.

Three-dimensional organization and dynamics of vortices in multichannel swirling jets

The unsteady three-dimensional flow organization of jets issued from a duct with swirl vanes at Reynolds number equal to 1000 and swirl number $S$ ranging between 0 and 0.8 is investigated. Time-resolved tomographic particle image velocimetry returns the instantaneous flow structure and its evolution by visualization of velocity and vortical features. The most relevant coherent motions are identified and characterized with the aid of dynamic mode decomposition. The time-averaged flow topology indicates that the vanes used to impart the swirling motion have a significant impact on the azimuthal modulation of momentum, with the jet exhibiting four sectors separated by a thin cross-like wake resulting from the boundary layer developed along the vane walls. The flow field is thus characterized by inner and outer shear regions. An increase in swirl, up to moderate levels ($S=0.4$), causes larger jet spreading angles. Further increase of the swirl number is accompanied by the appearance of a central recirculation zone due to vortex breakdown at $S=0.6$ which increases in size and is triggered upstream for increasing $S$. Although no shear layer instability development is observed at $S=0$, already at $S=0.2$ the swirling motion promotes the growth of helical vortices appearing as Kelvin–Helmholtz waves that deform the outer axial shear layer. The downstream evolution features successive pairing, which is observed for all the considered swirl numbers. The initial development of the instability is independent for each vane, whereas a mutual interaction between the vanes occurs after the vortex pairing. The reconnection from the four sectors vortices induces a significant increase of azimuthal vorticity, which affects the dynamical behaviour of the precessing vortex core. The latter is visualized by a low-order spatio-temporal reconstruction based on few dynamical modes. At a higher swirl number ($S\geqslant 0.6$), the axial vorticity component dominates the flow field; it interacts with the azimuthal vorticity, which penetrates inward through the meanders of the vane wakes and forces the vortex core precession and breakdown.

Improvement of two-phase flow distribution in the header of a plate-fin heat exchanger

The two-phase (liquid and gas) flow distribution in the header of a plate-fin heat exchanger was experimentally investigated. Small mass fractions of the liquid phase in the liquefaction process of natural gas were considered in this study. The liquid and gas flow velocity were measured using optical methods such as PIV/PTV/LIF. The flow maldistribution of liquid and gas flows was quantified and addressing this problem by attaching a porous baffle or modifying the inlet nozzle configuration was studied. The results showed that a vane swirler with a diffuser enhanced the flow distribution of both the liquid and gas phases fluid.

The effects of swirling decaying flow towards pipe entry length and heat transfer in an annular pipe

The hydrodynamic entry length of axial pipe flow has been studied extensively over the years. Entry length is used to identify range of fully developed flows as commonly used in many practical engineering applications (e.g. Moody’s chart). For laminar axial pipe flow, the hydrodynamic entry length has been investigated by Kays, Shah and Bhatti (KSB) (Lh = 0.056 ReDh). In contrast, several approximations exist for fully turbulent flows (i.e. 10 Dh–150 Dh). Through theoretical and numerical investigations, the hydrodynamic entry length for swirling decaying pipe flow in the laminar regime is investigated. It is found that, the development length Lh for the axial velocity profile is reduced when a rotational component is added to the mean flow. The reduction in the hydrodynamic length is found to be proportional to the inlet swirl angle θ and the magnitude of the rotational component. Results indicate that a modification can be made on the KSB equation for two-dimensional swirling annular pipe flow. This research also investigates the effect of the local swirl number and Reynolds number on the steady and unsteady heat transfer inside an annular pipe. The existence of the jet effect near the exit of the swirl vane altered the behaviour of the local heat transfer coefficient in the axial direction (along the pipe) for z = 0 mm to z = 40 mm. The heat transfer coefficient for the 30° vane angle is found to increase after z = 0 mm to a maximum value before decaying nonlinearly, whereas, for the 45° and 60° vane angles, the heat transfer coefficient decreases nonlinearly starting from the vane exit. It is found that, for low Re, Ts changes linearly over the course of the cooling zone for all vane angles. With increasing Reynolds number, the behaviour of the cooling curve changes from linear to nonlinear. Overall, the cooling time is found to be inversely proportional to Re. With increasing vane angle, the overall swirl number S along the pipe decreases, thus, reducing the overall swirling momentum in the annular pipe, leading to a lower heat diffusion rate. It is found that the dependency of the temperature of the solid rod Ts on Re is decreasing as Re increases.

Experimental investigation of in-cylinder air flow to optimize number of helical guide vanes to enhance DI diesel engine performance using mamey sapote biodiesel

The current research work investigates the influence of helical guide vanes in to the intake runner of a D.I diesel engine operating by the high viscous Mamey Sapote biodiesel to enhance in-cylinder suction air flow features. Helical guide vanes of different number of vanes are produced from 3D printing and placed in the intake manifold to examine the air flow characteristics. Four different helical guide vane devices namely 3, 4, 5 and 6 vanes of the same dimensions are tested in a D.I diesel engine operating with Mamey Sapote biodiesel blend. As per the experimental results of engine performance and emission characteristics, it is found that 5 vanes helical guide vane swirl device exhibited in addition number of increased improvements such as the brake power and bake thermal efficiency by 2.4% and 8.63% respectively and the HC, NOx, Carbon monoxide and, Smoke densities are reduced by 15.62%, 4.23%, 14.27% and 9.6% at peak load operating conditions as collate with normal engine at the same load. Hence this investigation concluded that Helical Guide Vane Devices successfully enhanced the in-cylinder air flow to improve better addition of Mamey Sapote biodiesel with air leading in better performance of the engine than without vanes.

An experimental study of interacting swirl flows in a model gas turbine combustor

In this experimental work, we analyze the flow structures emerging from the mutual interaction between adjacent swirling flows at variable degrees of swirl, issued into a semi-confined chamber, as it could happen in a three cup sector of an annular premixed combustor of a modern gas turbine engine. Stereoscopic particle image velocimetry (sPIV) is used to characterize both the non-reacting and reacting flow fields in the central diametrical (vertical) plane of the swirlers and the corresponding transverse (horizontal) planes at different heights above the swirlers. A central swirling flow with a fixed swirl vane angle is allowed to interact with its neighboring flows of varied swirl levels, with constant inlet bulk flow velocity through the central port. It is found that the presence of straight jets with zero swirl or co-rotating swirling jets with increasing swirl on both sides of the central swirling jet, significantly alters its structures. As such, an increase in the amount of swirl in the neighboring flows increases the recirculation levels in central swirling flow leading to a bubble-type vortex breakdown, not formed otherwise. It is shown with the aid of Helmholtz decomposition that the transition from conical to bubble-type breakdown is captured well by the radial momentum induced by the azimuthal vorticity. Simultaneous sPIV and OH-planar laser-induced fluorescence (PLIF) are employed to identify the influence of the neighboring jets on the reacting vortex breakdown states. Significant changes in the vortex breakdown size and structure are observed due to variation in swirl levels of the neighboring jets alongside reaction and concomitant flow dilatation.

PDA research on the air/particle flow characteristics in a 2000 t/d GSP pulverized coal gasifier at different swirl vane angles

On an air-particle test facility, a particle dynamics anemometer is employed to investigate, in a small-scale gasification chamber for a 2000 t/d GSP gasifier, the influence of burner swirl vane angle (SVA: 16°, 21°, 26° and 31°) on the air/particle flow characteristics. The distributions of three-dimensional air/particle velocity, particle volume flux and particle size were obtained. Further, a novel method was provided to quantify the air-particle mixture extent with dimensionless difference of particle volume concentration. The results show that along the jet flow direction, single peak, double peaks and single peak successively appeared in the profiles of mean axial velocities. As the SVA increased from 16° to 31°, the first appeared peak of mean axial velocities in the near-wall region (300 mm ≤ r ≤ 352 mm) gradually moved toward the burner; in the region x/d = 0.3–4, the central recirculation zone expanded. The profile variation of particle volume flux at different SVAs was basically similar to that of air mean axial velocity. In the same cross-sections of x/d = 1–4, as the SVA increased from 16° to 26°, the air-particle mixture extent in the boundary of peak zone for particle volume flux rose; when the SVA increased to 31°, it reduced.

Influence of swirl number on jet noise reduction using flat vane swirlers

In this work, jet noise reduction using a swirling flow surrounding a circular free jet has been demonstrated. The passive control scheme induces swirl from six flat vanes fixed in an annular passage with vane angles from 0 to 50°, with the corresponding swirl numbers ranging from 0 to 0.91. Noise measurements in terms of overall sound pressure levels, directivity patterns, acoustic spectra; and flow measurements in terms of centerline pitot survey and flow visualization have been carried out to evaluate the efficacy of the passive control scheme. The co-axial swirl jets always reduce the low frequency noise, irrespective of the nozzle pressure ratio. The screech tone is entirely eliminated and broadband shock associated noise mitigated by the co-axial swirl jets. The results of highly under expanded supersonic cases, show that, the weak swirl generates higher noise and high swirl generates lower noise for the same nozzle pressure ratio. The centerline pitot pressure measurements reveal that the co-axial swirl jets decrease the core lengths and the number of shock cells compared to the free jet. The flow visualization study shows that Mach disks are generated at lower pressure ratios for the co-axial swirl jets compared to free jet. The present work proposes swirl as an excellent passive tool for jet noise suppression.

Influence of the inlet flow swirler construction on hydrodynamics and efficiency of work

The object of research is construction of a vortex dust collector. To solve the problem of increasing the efficiency of dust cleaning in a vortex apparatus with revealing the features of the mechanism and the destructive forces of the process, the features of the hydrodynamic regime of rotation of the gas-dust flow in the zone of the swirler and immediately after it are used. The influence of the swirler construction and the location of its installation in the gas duct for feeding the gas-dust flow on the efficiency of the vortex apparatus is studied. It is shown that the aerodynamic processes that determine the nature of the flow rotation and its flow in the flue after the swirler reach the maximum possible angular velocity of the gas flow rotation in the separation chamber for this construction. It is proved that the swirler construction under the appropriate conditions allows a swirling flow leaving the duct to the separation chamber to reach the maximum possible angular velocity of the gas flow rotation for the given construction. The characteristic regimes of the gas-dust flow in the duct are established immediately after the swirler from its construction. It is shown that for a traditional vane swirler with a swirling flow in one direction, the most effective blade inclination angle corresponds to 45°. Its installation must be carried out in the duct from the end outlet to the separation chamber below by 1 . 4 ¸ 1 . 6 of the swirler diameter. Before the gas-dust flow flows into the separator, the flow is agglomerated with dust particles. At the exit of the gas-dust flow from the end of the flue to the separation space, the maximum value of the angular velocity of the flow in the separator is ensured. It is established that the blade vortex, which provides for the organization of coaxial turbulent flows in the flue, twisted in opposite directions, will allow more efficient agglomeration of dust particles. A basic construction of the vortex dust collector is developed, which makes it possible to increase the cleaning efficiency with a vortex device to 98–99 %.

Numerical investigation of the effects of rising angle on intermediate turbine duct and nearby turbines

In order to improve the efficiency, ultra-high bypass ratio engine attracts more and more attention because of its huge advantage, which has larger diameter low pressure turbine (LPT). This trend will lead to aggressive (high diffusion) intermediate turbine duct (ITD) design. It is necessary to guide the flow leaving high pressure turbine (HPT) to LPT at a larger diameter without any severe loss generating separation or flow disturbances. In this paper, eight ITDs with upstream swirl vanes and downstream LPT nozzle are investigated with the aid of numerical method. These models are modified from a unique ITD prototype, which comes from a real engine. Key parameters like area ratio, inlet height, and non-dimensional length of the ITDs are kept unchanged, while the rising angle (radial offset) is the only changed parameter which ranges from 8 degrees to 45 degrees. In this paper, the effects of rising angle (RA) on ITD, as well as nearby turbines, will be analyzed in detail. According to the investigation results, RA could be as large as 40 degrees in such model of this paper to escape separation; When RA increases, local inlet flow field of LPT nozzle appears to be with apparent variation; while a positive result is that outlet flow field could be kept almost unchanged through modifying blade profile. On the other hand, it seems optimistic that the overall total pressure loss could be kept nearly equivalent among different RA cases. And a valuable conclusion is that outer wall curvature is more important for pressure loss, which advises a clear direction for optimizing ITD.

Full-Scale Turbofan Demonstration of a Deployable Engine Air-Brake for Drag Management Applications1

This paper presents the design and full-scale ground-test demonstration of an engine air-brake (EAB) nozzle that uses a deployable swirl vane mechanism to switch the operation of a turbofan's exhaust stream from thrust generation to drag generation during the approach and/or descent phase of flight. The EAB generates a swirling outflow from the turbofan exhaust nozzle, allowing an aircraft to generate equivalent drag in the form of thrust reduction at a fixed fan rotor speed. The drag generated by the swirling exhaust flow is sustained by the strong radial pressure gradient created by the EAB swirl vanes. Such drag-on-demand is an enabler to operational benefits such as slower, steeper, and/or aeroacoustically cleaner flight on approach, addressing the aviation community's need for active and passive control of aeroacoustic noise sources and access to confined airports. Using NASA's technology readiness level (TRL) definitions, the EAB technology has been matured to a level of six, i.e., a fully functional prototype. The TRL-maturation effort involved design, fabrication, assembly, and ground-testing of the EAB's deployable mechanism on a full-scale, mixed-exhaust, medium-bypass-ratio business jet engine (Williams International FJ44-4A) operating at the upper end of typical approach throttle settings. The final prototype design satisfied a set of critical technology demonstration requirements that included (1) aerodynamic equivalent drag production equal to 15% of nominal thrust in a high-powered approach throttle setting (called dirty approach), (2) excess nozzle flow capacity and fuel burn reduction in the fully deployed configuration, (3) acceptable engine operability during dynamic deployment and stowing, (4) deployment time of 3–5 s, (5) stowing time under 0.5 s, and (6) packaging of the mechanism within a notional engine cowl. For a typical twin-jet aircraft application, a constant-speed, steep approach analysis suggests that the EAB drag could be used without additional external airframe drag to increase the conventional glideslope from 3 deg to 4.3 deg, with about 3 dB noise reduction at a fixed observer location.

Jet noise reduction using co-axial swirl flow with curved vanes

Experimental studies are carried out to reduce the jet noise using co-axial swirlers in the form of curved vanes fixed in an annular passage. The swirl numbers considered for the present work ranged from 0 to 1.31, and the corresponding swirl vane angles ranged from 0 to 60°. The nozzle pressure ratios studied ranged from 1.8 to 6. The acoustic far field study at subsonic conditions revealed the presence of transonic tones for the non-swirl jet. However, swirl eliminates the transonic tones and a weak swirl is most efficient for noise reduction at subsonic conditions. The centerline total pressure measurements indicate the reduced core length for the swirl jets compared to the non-swirl jets. At supersonic conditions, the non-swirl jet emits the highest noise at all the emission angles compared to the swirl jets. The swirl jets are free from screech tones, and have lower amounts of shock associated noise, even at high nozzle pressure ratios. The centerline total pressure measurements and schlieren visualization studies show that shock cell spacing and the number of shock cells are reduced in the swirl jets compared to the non-swirl jet.

An Experimental Study of Optimum Angle of Air Swirler Vanes in Liquid Fuel Burners

The present work shows that how the angle of an air swirler vane affects the combustion characteristics of liquid fuels such as flame temperature, radiation heat flux, combustion efficiency, and pollutants' emission. It finds out an optimum angle of vane based on flame characteristics. Three vanes with angles of 0 deg, 40 deg, and 80 deg which induced low and high-swirl intensities in air stream were investigated, and the combustion characteristics of flame were quantified. The flame temperature was measured by an S-type thermocouple, and a Testo 350 XL gas analyzer was used to determine the CO and NO pollutant concentrations. Also, gravity method was used to gauge the soot concentration along the furnace, and a SBG01 water cooled heat flux sensor determined the flame radiation. The results indicate that the angle of the swirler vane has significant effects on temperature, combustion efficiency, and NO and CO pollutants' emission. Most importantly, there is an optimum angle for the swirler vane. At the optimum angle, the optimum combination of the contact area and time maximizes the mixing rate of the inlet air and the fuel jet. Consequently, at the optimum angle, the mean temperature, radiation heat flux, and combustion efficiency are higher than at small and large swirl angles and soot, CO and NOx emissions are at their minimum states.

Characteristics of H2-enriched CH4[sbnd]O2 diffusion flames in a swirl-stabilized gas turbine combustor: Experimental and numerical study

The study presents the results of experimental and numerical investigations of oxy-combustion H2-enriched-CH4 diffusion flames in an atmospheric pressure swirl stabilized gas turbine model combustor. The flames characteristics in terms of temperature and species distributions, structures and flow fields are studied experimentally and numerically over ranges of operating parameters. The effects of equivalence ratio, oxidizer composition, H2-enrichment and swirl vane angle on flame stability, temperature distribution and flow field are studied in details. The swirl number considered in the experimental measurements is 1.10 with corresponding swirl vane angle of 55°. ANSYS Fluent was used to perform the numerical study and the models adopted are; k-ε (standard), discrete ordinate (DO), eddy-dissipation-concept (EDC) for turbulence, radiation, and species transport. Combined modified Jones–Lindstedt reaction mechanism and Marinov reaction mechanism for H2 were considered as reaction mechanism for the numerical study. The numerical results are in good agreement with their corresponding experimental data. It was observed that utilizing H2-enriched-CH4 improves the flame stability. The numerical results showed that oxy-fuel combustion of H2-enriched-CH4 is not achievable at an equivalence ratio of 0.95 and above due to stability issues. The stability is highly enhanced by the corresponding formation of inner recirculation zone. A swirler with swirl vane angle of 65° achieved better stability limits of the gas turbine combustor.

An Investigation on the Effect of Air Swirler Vane Angle on Liquid Fuel Combustion Characteristics

AbstractThis is an experimental and numerical study on the effect of air swirl vane angle on combustion characteristics of liquid fuel burners. The swirl vane angle varied in a range from 0° to 75° and the values of the dependent variables were determined. The flame temperature was measured by an S‐type thermocouple and a Testo 350 XL gas analyzer was used to determine the NO and CO pollutant concentrations. Also, sprint CFD code along with suitable models was used in analytical modeling. The results indicate that there is an optimum angle for the swirl vane (approximately 45° for the case study). At the optimum angle, the average temperature of the flame increases as much as 12.5% and 28.5% in comparison with small and large angles, respectively. Therefore, combustion efficiency reaches its maximum level and CO emission is at an extremely low level. The results also demonstrate that large swirl angles decreases NO emission.

Influence of Main Swirler Vane Angle on the Ignition Performance of TeLESS-II Combustor

In order to balance the low emission and wide stabilization for lean premixed prevaporized (LPP) combustion, the centrally staged layout is preferred in advanced aero-engine combustors. However, compared with the conventional combustor, it is more difficult for the centrally staged combustor to light up as the main stage air layer will prevent the pilot fuel droplets arriving at igniter tip. The goal of the present paper is to study the effect of the main stage air on the ignition of the centrally staged combustor. Two cases of the main swirler vane angle of the TeLESS-II combustor, 20 deg and 30 deg are researched. The ignition results at room inlet temperature and pressure show that the ignition performance of the 30 deg vane angle case is better than that of the 20 deg vane angle case. High-speed camera, planar laser induced fluorescence (PLIF), and computational fluids dynamics (CFD) are used to better understand the ignition results. The high-speed camera has recorded the ignition process, indicated that an initial kernel forms just adjacent the liner wall after the igniter is turned on, the kernel propagates along the radial direction to the combustor center and begins to grow into a big flame, and then it spreads to the exit of the pilot stage, and eventually stabilizes the flame. CFD of the cold flow field coupled with spray field is conducted. A verification of the CFD method has been applied with PLIF measurement, and the simulation results can qualitatively represent the experimental data in terms of fuel distribution. The CFD results show that the radial dimensions of the primary recirculation zone of the two cases are very similar, and the dominant cause of the different ignition results is the vapor distribution of the fuel. The concentration of kerosene vapor of the 30 deg vane angle case is much larger than that of the 20 deg vane angle case close to the igniter tip and along the propagation route of the kernel, therefore, the 30 deg vane angle case has a better ignition performance. For the consideration of the ignition performance, a larger main swirler vane angle of 30 deg is suggested for the better fuel distribution when designing a centrally staged combustor.

Experimental investigation of phase split of gas–liquid two-phase flow through small holes at the pipe wall

An experimental and analytical study on phase split of gas–liquid two-phase flow through small holes at the main pipe wall has been performed in this paper. The inner pipe diameter of the test section is 40mm and the diameter of sampling hole is 2.5mm. Experiments were conducted in an air–water two-phase flow loop and four types of sampler with different arrangement of sampling-holes were tested. Stratified-wavy, annular and slug flows were observed. Experimental results show that phase splitting behavior is significantly influenced by the number and positions of the sampling-holes and the superficial velocities of the gas and liquid. If a swirl vane is mounted at the upstream of the four-hole sampler, an interesting phenomenon that the liquid extraction ratio maintains constant and is independent of the inlet flow patterns can be observed.

Rectangular jet with shear layer swirl: Rotation & mixing enhancement

A rectangular jet emerging from a nozzle with embedded swirl vanes in its exit boundary layer is studied. The swirling shear layer imposes an external torque on the jet boundary where it causes jet rotation in the direction of axis switching, skew deformation as well as enhanced mixing. In moderate aspect ratio rectangular nozzles, e.g. AR = 5:1, a pair of co-rotating streamwise vortices is formed on the narrow boundary of the jet that dominates its dynamics in the near field. A vortex-induced model is developed that accounts for the rotation of the rectangular jet with embedded shear layer swirl. The model also shows that the jet rotation is diminished with increasing aspect ratio, as AR−2. The higher entrainment rate in the rotating jet with skew deformation causes the jet mass flow rate with shear layer swirl to be 20–25% higher than the corresponding plain rectangular nozzle of the same aspect ratio (x/De > 1). The proposed model is validated using computational simulation results of previous investigations that appeared in the literature.

Heat transfer and friction characteristics of shell and tube heat exchanger with multi inserted swirl vanes

The effect of friction characteristics of the heat exchanger model when using different number of swirl vanes at different locations along the pipe length to enhance the heat transfer rate will be discussed through a simulation for shell and tube heat exchanger using ANSYS FLUENT CFD techniques. The number of swirl vanes inserted into each tube is three swirl vanes and six swirl vanes distributed along the pipe length with variable diameter (10mm, 15mm, 19mm) and different blade angle (15°, 30°, 45°) for each case. The results show that the numerical results reasonably agree well with the available literature. The case of six swirl vanes with 19mm diameter and 45° blade angle gives the maximum heat transfer enhancement, friction factor, and thermal enhancement factor compared with plain tube case. A correlation for Nusselt number and friction factor is developed.