Order Upwind Research Articles

An improved consistent, conservative, non-oscillatory and high order finite difference scheme for variable density low Mach number turbulent flow simulation

A consistent, conservative and truly high order finite difference scheme for low Mach number turbulent variable density flow simulation is presented. In the present scheme, the scalar transport equation is discretized with the explicit weighted compact nonlinear scheme (WCNS) while the continuity and momentum equations are discretized with a conservative centered high order finite difference scheme on a staggered grid. Bounded hybrid high order upwind interpolation is proposed for the evaluation of density on the cell faces of the staggered grid. The use of explicit WCNS along with the bounded density interpolation resolves the issue of degraded order of accuracy in the existing high order finite difference schemes where the centered finite difference scheme for mass and momentum conservation is combined with a total variation stable scheme for scalar transport. With the same difference operator used for the continuity and scalar transport equations, the present scheme is consistent naturally, and resolves the inconsistency problem reported in Trisjono et al. (2016) [6] without employing any modification to a scheme. Such improvements are demonstrated for several test cases.

Numerical optimization of the mixing flow in a straight tube, single, and two loops helical coil

<p>A great interest of using curved pipes was shown in the industrial applications due to many advantages such as developed agitation which could be obtained as an alternative to the conventional agitation at lower energy consumption and reduced cost. A computational investigation was conducted in this study to contemplate on the enhancement occur in the mixing flow upon using single and multi-loops helical coil compared with a straight tube. The objective was to optimize the number of loops in the helical coil. The computations were achieved via “Fluent software” in which 3d, second order upwind were used for all cases studied. The study consisted of four parts in which the numerical error study was conducted in the first part to optimize the grid meshing and to make sure that the results are independent of it. The effect of using the helical coil on the pressure drop was conducted in the second part. The third and fourth parts of the study were devoted to envisage the enhancement of applying the curved loops in the coil on the heat and mass transfer, respectively. The main findings of the study were limited effect of single loop coil on the heat and mass transfer processes. Better effect was depicted upon increasing the number of loops in the helical coil into 2. However, applying 2 loops has resulted in building up higher pressure drops. Moreover, the pressure drop was shown slightly higher in the case of applying water when compared with air.</p>

A Model to Predict the Influence of Inconsistencies in Thermal Barrier Coating (TBC) Thicknesses in Pistons of IC Engines

LHR (Low heat Rejection) engines comprise of components that are modified with ceramic Thermal Barrier Coatings (TBC) to derive improvements in performance, fuel efficiency, combustion characteristics and life. In addition to engine parameters, the ability of TBCs (250 - 300µm thick) to function favorably depends on materials technology related factors such as surface-connected porosity, coating surface roughness, uniformity and consistency in coating thickness [1]. Right since the nineties, emphasis has been placed on the complexity of piston contours from a coating processing standpoint because the piston bowl geometry although appears simple, is actually quite complex. Robotic plasma gun manipulation programs have been developed to obtain uniform coating properties and thicknesses which are highly classified information.Thicker coatings offer better thermal insulation characteristics but in thickness deficient regions, TBCs may be as thin as ∼30 microns. Applied via the ‘line of sight’ process, in the Atmospheric Plasma Spray System the coating thickness does not get developed adequately if the components comprise of contours with shadow regions. Thus the coating quality of a LHR engine heavily depends upon the shape of the engine components. This affects the barrier effects offered by the TBC and is reflected via generation of unwanted thermal gradients in the combustion chamber and on the external piston walls that adversely influence the engine performance.Extensive diesel engine cycle simulation and finite-element analysis of the coatings have been conducted to understand their effects on (a) diesel engine performance and (b) stress state in the coating and underlying metal substructure. Research work presented here involves the need and developmental efforts made via Computational Fluid Dynamics (CFD) to generate a model via ANSYS - Fluent simulation software that predicts the temperature gradient across TBCs of various ceramics and coating thicknesses. The geometric model was developed using the dimensions obtained using a CMM (Coordinate Measuring Machine) in Solidworks and the mesh was developed in Altair Hypermesh. The generated mesh consists of 221938 elements. Interfaces were created between the piston-bond coat-top coat surfaces. The Ansys-FLUENT CFD code solves the energy equation to find out the temperature drop in the piston for different combustion temperatures. Although most of the cavities presented are not rectangular, incompressible and steady laminar flow was assumed. The Semi-Implicit Method for Pressure-linked Equations (SIMPLE) was used to model the interaction between pressure and velocity. The energy variables were solved using the second order upwind scheme. In addition, the CFD program uses the Standard scheme to find the pressure values at the cell faces. Convergence was determined by checking the scaled residuals and ensuring that they were less than 10-6 for all variables.Two cases with combustion temperatures varying between 700 and 800 K were developed in Ansys FLUENT, wherein the thickness was deficient in the ‘shadow’ region. The model was validated via experimentation involving thermal shock cycle tests in prototype burner rig facility and measuring the temperature drop across the TBC as well.Non uniform coatings, leading to non-uniform drop in temperature across the thickness are most likely to affect the lubrication system of the engine and therefore the performance. Substantial efforts must be directed towards development of consistent and uniformly thick coatings for optimum performance of the LHR engine.

Phase field simulation of Rayleigh–Taylor instability with a meshless method

The purpose of this paper is a numerical study of Rayleigh–Taylor instability problem in two dimensions, based on phase-field (PF) formulation and diffuse approximate method (DAM) meshless solution procedure, enabling single-domain fixed-node approach for coping with moving boundary problems. The problem is formulated based on three physically different models that reduce to solving Cahn–Hilliard equation in addition to the Navier–Stokes equations for incompressible fluids. The governing equations are solved by using explicit time discretization. DAM is structured with second order polynomial basis, Gaussian weighting, upwinding and local domain support. The pressure–velocity coupling is performed by the fractional step method. The assessment of the method is carried out based on different node density, weighting, and the size of the local domain support. The novel approach is verified by reproducing the boundary dynamics, consistent with the previously published results. A detailed comparison with the volume of fluid finite volume approach is presented. The combination of PF and DAM provides a valuable numerical tool for solving immiscible convective hydrodynamics problems. The paper represents a pioneering attempt in solution of Rayleigh–Taylor instability problem by a meshless solution of the phase-field formulation of the problem.

Combined natural convection and thermal radiation in an inclined cubical cavity with a rectangular pins attached to its active wall

Three dimensional combined natural convection and thermal radiation in an inclined cubic enclosure with pins attached to the active wall is investigated numerically. The vertical opposing walls are heated and cooled while the other walls are assumed to be adiabatic. The governing flow, momentum equations and the radiative transfer are solved using Fluent® 6.3 CFD software. In the discretization of the convection terms, the second order upwind scheme and for the solution algorithm SIMPLE is used. The cubic enclosure is filled with air and the flow is considered to be laminar. The properties of air are assumed to be constant except for the density variation for which the Boussinesq approximation is used. The surface to surface (S2S) heat model is used as the radiation transfer model. The computations are performed for Rayleigh number in the range 103≤Ra≤106 and for the surface emissivity (e) 0≤e≤1 while the inclination angle is varied 0°≤φ≤75°. The mean Nusselt number for convection and radiation transfer were evaluated as a function of Rayleigh number, emissivity and inclination angle and for some cases, the fluid flow and the temperature distributions were analyzed. The results showed that the mean total and radiative Nusselt number increases monotonically with increasing Ra number and the surface emissivity.

Numerical Study of Temperature and Air Velocity Distribution In Oil Filling Factory

This paper describes the use of CFD modeling to analyze the thermal comfort in the oil filling factory which has an area of 3000 m 2. the need for this analysis comes from an uncomfortable condition that is felt by the workers of the factory. A 3D simulation using FLUENT software 6.3.26 conducted to analyze the temperature and velocity distribution in the plant room. The water is assumed as an incompressible ideal gas, steady flow, turbulence models used k-e standard, the SIMPLE algorithm and second order upwind discretisation. Analysis was conducted on existing models and propose models, whereby on a model propose, the diffuser is installed above the workers with a height of 4,2 m above the floor, the velocity of supply air diffuser is varied from 1,5 m/s, 2 m/s, and 2,5 m/s. The simulation results show that the temperature distribution in the existing conditions in the range of about 34-36 ° C, this value exceeds the thermal comfort standards specified by ASHRAE. The simulation results show that the proposed model better temperature distribution, where the temperature is generated in the range of ASHRAE thermal comfort criteria, ranging from 24-26 °C, and the supply air velocity at the diffuser inlet of 1,5 m/s recommended for use in AHU system. For the 20 units of the diffuser with inlet velocity of 1,5 m / s, the mass flow rate that should be handled by a cooling device is 9 kg/s and require a cooling capacity of 0,128 MW. This is 58% more efficient than cooling the entire room factory.

Numerical Simulation for the Combustion of a Zirconium/ Potassium Perchlorate Explosive inside a Closed Vessel

AbstractThe combustion of zirconium potassium perchlorate (ZPP) in a closed vessel is modelled and validated through a numerical simulation. Because the extremely high pressure oscillation occurs in less than a millisecond, an in‐house computational fluid dynamics (CFD) code is used to observe the detailed flow structures and determine the adequate burning characteristics, including the burning rate. A hybrid RANS/LES scheme with a 5th order upwind weighted essentially non‐oscillatory (WENO) is implemented to capture complex, strong shock waves in highly turbulent combustion. A two‐way coupled Eulerian‐Lagrangian scheme tracks the combusting ZPP granules reasonably well. Monodisperse and Rosin‐Rammler assumptions are applied to the ZPP granule distribution. The monodisperse assumption reveals that the diameter of the ZPP (17 μm) achieves marginal agreement with the measurements. However, the Rosin‐Rammler distribution improves the transient and dynamic combustion characteristics in that the small granules contribute to a faster burning rate and stronger shock waves. These results are more analogous to the closed vessel tests used as validation data.

Effect of uniform and nonuniform heat source on natural convection flow of micropolar fluid

Natural convection of micropolar fluid in a square cavity with uniform and nonuniform heated thin plate built in horizontally or vertically is investigated numerically. The non-uniform heating is due to the non-linearly varying temperature of the plate. The vertical walls are cooled while the top and bottom walls are insulated. The flow with in the cavity is assumed to be two dimensional. The governing equations were solved by finite volume method using second order central difference scheme and upwind differencing scheme. The computational results are presented in the form of isotherms, streamlines and average Nusselt numbers. The study was performed for different Rayleigh numbers, Prandtl numbers, length of the heat source, location of the plate, vortex viscosity parameter and source non-uniformity parameters. The result shows that the presence of vortex viscosity parameter retards the fluid velocity and hence the heat transfer rate is decreased. Also, the non-uniformity parameter affects the fluid flow and heat transfer rate especially for higher Rayleigh numbers.

Numerical simulation of laminar convection heat transfer from an array of circular perforated fins

The present paper reports the laminar fluid flow and heat transfer of a heated array of circular-perforated and solid fins mounted over a flat surface using the finite-volume method. One to four circular cross-sectional perforations are made along the length of the fins. The SIMPLE algorithm is used for pressure-velocity coupling and the second order upwind technique is employed to discretize the governing equations. The simulations are done for a range of Reynolds number, 100 < Re < 350, corresponds to the flow velocity of 0.37-1.28 m/s. The average Nusselt number, the average friction factor coefficient, and the perforated-fin effectiveness are calculated. The results demonstrated that for any Reynolds number, the heat transfer decreases and the friction factor increases with the number of perforations. It was observed that the fin with circular perforation had a higher effectiveness in comparison with the rectangular-perforated fins.

Finite volume lattice Boltzmann scheme for neutron/radiative transfer on unstructured mesh

In this paper, we propose a novel finite volume lattice Boltzmann (FV-LB) scheme to simulate the neutron and radiative transfer problems governed by the linear Boltzmann transport equation (BTE). In the derivation of the FV-LB scheme, we utilize a multi-speed lattice Boltzmann model to reduce the linear BTE into a linear discrete velocity Boltzmann equation (DVBE). Considering the computational effectiveness and flexibility in complex geometries, we design a finite volume scheme by using the first order upwind numerical flux and solve the DVBE with the finite volume scheme on a unstructured tetrahedral or triangular mesh. The accuracy of the FV-LB scheme is verified by comparing our results with the benchmark values of three representative problems.

Benchmark studies of BOUT++ code and TPSMBI code on neutral transport during SMBI

SMBI (supersonic molecule beam injection) plays an important role in tokamak plasma fuelling, density control and ELM mitigation in magnetic confinement plasma physics, which has been widely used in many tokamaks. The trans_neut module of BOUT++ code is the only large-scale parallel 3D fluid code used to simulate the SMBI fueling process, while the TPSMBI (transport of supersonic molecule beam injection) code is a recent developed 1D fluid code of SMBI. In order to find a method to increase SMBI fueling efficiency in H-mode plasma, especially for ITER, it is significant to first verify the codes. The benchmark study between the trans_neut module of BOUT++ code and the TPSMBI code on radial transport dynamics of neutral during SMBI has been first successfully achieved in both slab and cylindrical coordinates. The simulation results from the trans_neut module of BOUT++ code and TPSMBI code are consistent very well with each other. Different upwind schemes have been compared to deal with the sharp gradient front region during the inward propagation of SMBI for the code stability. The influence of the WENO3 (weighted essentially non-oscillatory) and the third order upwind schemes on the benchmark results has also been discussed.

Lattice Boltzmann simulation for high-speed compressible viscous flows with a boundary layer

• A coupled DDF-LB model was used to simulate high-speed compressible viscous flows. • NND and second-order upwind difference schemes were compared in simulations. • The DDF-LB model could simulate a compressible boundary layer up to Ma = 6. • Local high pressure appeared with the shock wave due to LBM’s mesoscopic feature. • High potential of LBM was shown for the shock boundary layer interaction problem. In this study, the lattice Boltzmann method is employed for simulating high-speed compressible viscous flows with a boundary layer. The coupled double-distribution-function lattice Boltzmann method proposed by Li et al. (2007) is employed because of its good numerical stability and non-free-parameter feature. The non-uniform mesh construction near the wall boundary in fine grids is combined with an appropriate wall boundary treatment for the finite difference method in order to obtain accurate spatial resolution in the boundary layer problem. Three typical problems in high-speed viscous flows are solved in the lattice Boltzmann simulation, i.e., the compressible boundary layer problem, shock wave problem, and shock boundary layer interaction problem. In addition, in-depth comparisons are made with the non-oscillatory and non-free-parameter dissipation (NND) scheme and second order upwind scheme in the present lattice Boltzmann model. Our simulation results indicate the great potential of the lattice Boltzmann method for simulating high-speed compressible viscous flows with a boundary layer. Further research is needed (e.g., better numerical models and appropriate finite difference schemes) because the lattice Boltzmann method is still immature for high-speed compressible viscous flow applications.

Finite volume schemes for the numerical simulation of tracer transport in plants

Compartmental models can be used for inverse modeling of long distance tracer transport experiments in plants. Such transport models describe axial convection and diffusion as well as exchange between compartments, and are defined by partial differential equations (PDEs). Since for inverse modeling, the forward simulation needs to be evaluated frequently, a fast PDE solver is required. Here, we compare several different finite volumes schemes up to fifth order for spatial discretization with respect to accuracy, computation time and numerical oscillations. The comparison has been performed using initial conditions with varying steepness, and periodic boundary conditions. For time discretization, standard fifth order Runge–Kutta methods are used. For smooth initial conditions, fifth order upwind schemes for spatial discretization yield the most precise and fast solutions. For higher steepness of the initial condition, higher order upwind schemes produce spurious oscillations while flux limiter schemes as well as weighted essentially non-oscillating (WENO) schemes can suppress these oscillations, at the expense of comparably slower convergence rates and higher computation times.

The development and validation of a natural circulation analysis code for marine reactors

ABSTRACTA code PNCMC (Program for Natural Circulation under Motion Conditions) has been developed for natural circulation simulation of marine reactors. The code is based on one-dimensional two-fluid model in noninertial frame of reference. The body force term in the momentum equation is considered as a time dependent function, which consists of gravity and inertial force induced by three-dimensional ship motion. Staggered mesh, finite volume method, semi-implicit first order upwind scheme and Successive Over Relaxation (SOR) method are used to discretize and solve two-phase mass, momentum and energy equations. Single-phase natural circulation experiments under rolling condition performed in Institute of nuclear and new energy technology of Tsinghua University and two-phase natural circulation experiments under rolling condition performed by Tan and colleagues are used to validate PNCMC. The validation results indicate that PNCMC is capable to investigate the single-phase and two-phase natural circulation under rolling motion.

Inflow-Based Gradient Finite Volume Method for a Propagation in a Normal Direction in a Polyhedron Mesh

An inflow-based gradient is proposed to solve a propagation in a normal direction with a cell-centered finite volume method. The proposed discretization of the magnitude of gradient is an extension of Rouy---Tourin scheme (SIAM J Numer Anal 29:867---884, 1992) and Osher---Sethian scheme (J Comput Phys 79:12---49, 1988) in two cases; the first is that the proposed scheme can be applied in a polyhedron mesh in three dimensions and the second is that its corresponding form on a regular structured cube mesh uses the second order upwind difference. Considering a practical application in three dimensional mesh, we use the simplest decomposed domains for a parallel computation. Moreover, the implementation is straightforwardly and easily combined with a conventional finite volume code. A higher order of convergence and a recovery of signed distance function from a sparse data are illustrated in numerical examples on hexahedron or polyhedron meshes.

On the Modeling of Air Flow in the Tombs of the Valley of Kings

The tombs of the kings in Valley of the Kings, Luxor, are considered to be one of the tourism industry’s bases in Egypt due to their uniqueness all over the world. Hence, they should be preserved from the different factors that might cause harm for their wall paintings. One of these factors is the excessive relative humidity as it increases the bacteria and fungus activity inside the tomb in addition to its effect on the mechanical and physical properties of materials. This chapter describes the Research work to design ventilation systems to some of these important tombs. The chapter aims to investigate, design, and implement controlled climate to the tombs of the valley of kings with complete monitoring of air properties, temperature, relative humidity and carbon oxides and air quality parameters mechanical distributions inside selected tombs of the valley of the kings that are open for visitors. A complete climate control and monitoring of air will be effected with the aid of a mechanical ventilation system extracting air at designated locations in the wooden raised floor of the tombs. The location, size and extracted air are to be predicted and optimized the use of Computational Fluid Dynamics software (CFD). The CFD modelling techniques would solve the continuity, momentum, energy, and species transport equations in addition to k-epsilon model equations for turbulence closure. The SIMPLEC algorithm is used for the pressure-velocity coupling and a second order upwind scheme was use for discretization of the governing equations. Mesh sizes used in the present work exceeded 700,000 mesh volumes to adequately represent the flow characteristics at various locations. Throughout the first phase of this investigation, the outside air conditions, number of visitors, and airside system design effect on the tombs’ airflow characteristics will be studied in order to reach the optimum ventilation design as well as the favourable working conditions for a particular tomb. Mechanical engineering design of air flow system including under raised floor flexible duct routings, sizes, grills locations etc. with be provided in professional design drawing to be used as bases for execution and installation at the second phase. A complete set of measuring and monitoring equipment will be installed for each tomb to intelligently direct the visitors to the tomb where relative humidity and CO2 levels are permissible. A permissible number of the simultaneous of visitors for each tomb should be made in order to limit the relative humidity inside any given tomb.

Evaluating the environmental parameters affecting the performance of photovoltaic thermal system using nanofluid

PV/T is a hybrid system which combines photovoltaic cells and solar collector. It can produce renewable electricity and heat, simultaneously. The aim of the present work is to study the effects of two environmental parameters on the performance of system. Also, the performance of pure water and Al2O3-water nanofluid are compared. The conduction and convection heat transfer are considered by CFD method. The mass, momentum, and energy equations are solved using the ANSYS Fluent. The second order upwind is selected as an interpolation scheme and the pressure-based solver is used for this laminar model. The pressure-velocity coupling method is the SIMPLE. Also, the gradients of the solution variables are determined by the least square cell based. The effects of solar radiation and fluid inlet temperature on the performance are modeled. Increasing the solar radiation reduces electrical efficiency; then, the thermal efficiency becomes fixed after a first rise. Nevertheless, the thermal efficiency remains fixed; the electrical efficiency decreases with increasing the fluid inlet temperature. The findings indicate that the heat transfer coefficient and the efficiency of Al2O3-water nanofluid are greater than pure water. The numerical model is validated by comparing the simulation results with the experimental data in the literature.

Parallel vertex approximate gradient discretization of hybrid dimensional Darcy flow and transport in discrete fracture networks

This paper proposes a parallel numerical algorithm to simulate the flow and the transport in a discrete fracture network taking into account the mass exchanges with the surrounding matrix. The discretization of the Darcy fluxes is based on the Vertex Approximate Gradient finite volume scheme adapted to polyhedral meshes and to heterogeneous anisotropic media, and the transport equation is discretized by a first order upwind scheme combined with an Euler explicit integration in time. The parallelization is based on the SPMD (Single Program, Multiple Data) paradigm and relies on a distribution of the mesh on the processes with one layer of ghost cells in order to allow for a local assembly of the discrete systems. The linear system for the Darcy flow is solved using different linear solvers and preconditioners implemented in the PETSc and Trilinos libraries. The convergence of the scheme is validated on two original analytical solutions with one and four intersecting fractures. Then, the parallel efficiency of the algorithm is assessed on up to 512 processes with different types of meshes, different matrix fracture permeability ratios, and different levels of complexity of the fracture network.

Cylindrical‐conical spouted bed dynamics: Laminar and turbulent flow predictions

AbstractThis work numerically studies transient behaviour of particulate flows in a cylindrical‐conical spouted bed in terms of comparative analysis of different models’ predictions. Two approaches were used: a laminar flow model and a turbulent flow model. As a reference case, we consider experimental studies by He et al.,[14,15] where the profiles of vertical particle velocities and the void fraction in the spout and the fountain of a full‐column spout bed were measured. In this work we used the Euler‐Euler unsteady multiphase model with the Syamlal‐O'Brien, Gidaspow, and Wen‐Yu drag models available in commercial CFD software Fluent 14.0. Analysis of results obtained by the use of laminar and turbulent flow models revealed almost identical solid and gas phase velocities and phase fractions within the spouted bed region. We found that the turbulence plays a significant role only in the gas phase above the spouted bed and it does not have any influence on the solid phase. Comparing our simulation results in the form of time‐averaged vertical velocity of the solid phase against experimental data showed acceptable agreement in the spout and very good agreement in the fountain region. Numerical simulations with the Syamlal‐O'Brien drag model gave better agreement with experimental data than results obtained using the Gidaspow and Wen‐Yu drag models. To analyze the transient behaviour of the spouted bed, we use the volume‐averaged particle velocity and gas phase velocity. The analysis of their time histories showed that the start up time is 2–3 s. The developed unsteady regime is reached after 4–5 s. Additionally we studied numerically the influence of different discretization schemes for convective terms on the final results. We found that the use of 1st order upwind scheme gives a steady state solution for both models, laminar and turbulent. Finally, we investigated the influence of the restitution coefficient on the transient characteristics of a cylindrical‐conical spouted bed. A decrease in the value of the restitution coefficient leads to an increase in the period of oscillations of the volume‐averaged velocities of the gas and solid phases.

Numerical study on boundary layer control using CH4[sbnd]H2[sbnd]air Micro-reacting jet

The focus of present numerical study is on assessment of control of laminar separation bubble phenomenon using Micro-scale combustion actuators in an airfoil with low Reynolds number under surface effect and free flows. In this way, the characteristics of laminar separation bubble such as its formation, geometry, and transition from laminar to turbulent around airfoil SD8020 in attack angles of 5 and 8° are investigated. Following that, the new combustion actuators in Micro-scale, cold, and hot air-jet injection are introduced to control boundary layer flow in terms of eliminating the separation bubble. Some mechanisms are identified for improvement of methane-air premixed flame stabilization in a Micro-scale combustor, which includes effects of added hydrogen to methane as an additive, a central conductive wire insertion, and creating steps in the reactor. The finite volume method is used to solve the turbulent unsteady flow equations. The results are compared with experimental and numerical data obtained by other researchers and show good conformity for aerodynamic coefficient predicting. The SIMPLE-C method is used in numerical algorithm utilized to coupling pressure and velocity fields, the second order upwind method is used to discretization of momentum equation, and finally SST Transient k-ω equations is used for turbulent flow modeling. The results show that the selected numerical method is able to recognize reverse pressure gradient, laminar separation bubble, and flow transition from laminar to turbulent in boundary layer. The bubble formation location and flow transition are also inclined towards airfoil leading edge under surface effect, and pressure distribution makes a variation in laminar separation bubble formation location. The utilization of combustion actuators leads to a decrease in flow Reynolds number along with airfoil wall and a tendency of flow to relaminarization. This causes a larger increase in the lift coefficient than the hot-air-jet injection. But additionally the friction effects on the surface is increased by laminar flow, that leads to an increase in friction drag coefficient of reacting jet rather than the hot-air jet and generally an increase in drag coefficient. On the other hand, the stall phenomenon control by combustion actuator also leads to an increase in stall angle limit from 10 to 14°, and lift coefficient improvement to 26% than without jet injection, through flow separation delay.