Stagnation Line Research Articles

Experimental investigation on the efficiency of circular cylinder-based wind energy harvester with different rod-shaped attachments

The performance of a circular cylinder-based piezoelectric wind energy harvester with two small-size rod-shaped attachments on the main circular cylinder was experimentally investigated. The rod had three different cross-sectional shapes: circular, triangular, and square. The two rods were attached on two sides of the main circular cylinder at a series of circumferential locations. They were parallel to the cylinder axis and symmetrical to the stagnation line. It was found that attaching these three rod types at the circumferential locations of 45° and 60°, harvested power continuously beyond the critical wind speed. It was, therefore, dramatically superior over both the plain circular cylinder and the cases with other attachment locations. Additionally, the output voltage for a circumferential location of 60° was greater than that 45° one over the whole working wind speed range. Furthermore, attaching the triangular rods on the main circular cylinder showed a better performance than the other two rod types. The force measurement results indicated that the circular cylinder with triangular rods at the circumferential location of 60° had larger transverse force coefficients than the other two rod type cases, verifying the findings in the energy harvesting tests. Therefore, it is recommended to attach two triangular rods at the circumferential location of 60° on the main circular cylinder in order to enhance the performance of a circular cylinder-based wind energy harvester.

Control of circular cylinder flow using distributed passive jets

A wind tunnel study has been carried out to investigate flow control around a hollow circular cylinder using passive jets driven by naturally occurring pressure differences. Flow enters the cylinder through spanwise holes along the stagnation line and exits through a spanwise distribution of holes at$\pm 65^{\circ }$. The diameter of the entry and exit holes were 1 % and 0.5 % of the cylinder diameter, respectively. Reynolds numbers were at the upper end of the subcritical regime and ranged from$3\times 10^{4}$to$2.8\times 10^{5}$. Jet spacings of 10 % and 20 % of the cylinder diameter were investigated, and the ratio of the average jet exit velocity to the cross-flow velocity at the boundary layer edge was found to rise to approximately 0.35 and 0.4, respectively, above a Reynolds number of$1.5\times 10^{5}$. Findings based on using the surface oil flow technique revealed a repeating, organised cellular pattern downstream of adjacent jet exit holes consisting of a primary counter-rotating vortex pair structure, followed by a secondary weaker pair. Downstream of adjacent exit holes, and centred midway between them, there exists a separation bubble which delays final flow separation compared with the flow directly downstream of a jet. The variation in the angular position of boundary layer separation across the span had the effect of suppressing von Kármán vortex shedding. This resulted in a drag coefficient, at the upper end of the Reynolds-number range studied, 14.5 % lower than that found using trip wires to initiate boundary layer transition.

Induced-charge electrokinetics in rotating electric fields: A linear asymptotic analysis

Concerning the electroconvective analyte manipulation in microfluidics, we describe the basic physics of fluid flow driven by rotating induced-charge electro-osmosis (ROT-ICEO), which occurs on the planar surface of a single floating electrode in an external rotating electric field. First, based on a linear asymptotic analysis, the dynamic flow stagnation line in ROT-ICEO induced on the bipolar electrode from a rotary Debye screening charge revolves synchronously with the applied rotating fields. A net hydrodynamic torque is then generated that acts on any fluid or particle sample to produce either a synchronous or asynchronous co-field rotation depending on the frequency of the ac signal. Next, from the synergy between the hydrodynamic and electrochemical ion relaxations, an analytical solution of the sample rotation rate subject to ROT-ICEO slipping on an ideally polarizable surface is obtained for different frequency ranges and determined by the transient nature of the rotating electro-osmotic flow oscillating at twice the field frequency. To visualize the flow field in ROT-ICEO, experiments were performed with fluorescent tracer nanoparticles; they exhibited concentric rotational behavior at the polarized phase interface. Formed like the arms of a nebula disk, the four twisted tails of nanoparticles can be arbitrarily directed under voltage-phase rectification. These experimental results are in good agreement with our mathematical simulations using the Debye–Hückel approximation on ROT-ICEO.

Influence of Turbine Blade Leading Edge Profile on Film Cooling With Shaped Holes

This paper presents the turbine blade leading edge model film cooling effectiveness with shaped holes, using the pressure sensitive paint (PSP) mass transfer analogy method. The effects of leading edge profile, coolant to mainstream density ratio, and blowing ratio are studied. Computational simulations are performed using the realizable k–ɛ (RKE) turbulence model. Effectiveness obtained by computational fluid dynamics (CFD) simulations is compared with experiments. Three leading edge profiles, including one semicylinder and two semi-elliptical cylinders with an after body, are investigated. The ratios of major to minor axis of two semi-elliptical cylinders are 1.5 and 2.0, respectively. The leading edge has three rows of shaped holes. For the semicylinder model, shaped holes are located at 0 deg (stagnation line) and ±30 deg. Row spacing between cooling holes and the distance between impingement plate and stagnation line are the same for three leading edge models. The coolant to mainstream density ratio varies from 1.0 to 1.5 and 2.0, and the blowing ratio varies from 0.5 to 1.0 and 1.5. Mainstream Reynolds number is about 100,000 based on the diameter of the leading edge cylinder, and the mainstream turbulence intensity is about 7%. The results provide an understanding of the effects of leading edge profile on turbine blade leading edge region film cooling with shaped hole designs.

Computational simulation of radially asymmetric hydraulic jumps and jump–jump interactions

Circular hydraulic jump (CHJ) and its deviation from the azimuthal symmetry due to non-orthogonal impingement of liquid jet on a solid surface are studied using finite volume based numerical framework. Asymmetric interfacial jump has been modelled from volume of fluid (VOF) prediction for a different angle of inclination of a jet from normal of the surface. The extent of asymmetry is found to be increasing as the jet becomes more and more horizontal, deviation from orthogonal impingement. To understand the role of wall adhered jet on jump, flow physics has been studied which reveals back flow in the jump region causing circulation. Moreover, equipotential and heterogeneous jump–jump interactions are studied to predict fluidic features like fountain formation and upwash. Numerical simulations reveal that strength of interacting wall jets play a major role in the formation of a pattern as consequence of neighbouring twin jet impingement. A vertical flat liquid protrusion is observed at equidistant stagnation line from the impingement points of equipotential jets. On the other hand, a curvilinear upwash film has been found out as characteristics of the interaction between heterogeneous strengths of interacting jets. At a higher ratio of jet strengths, complete engulfment of a smaller hydraulic jump as an eye of larger one has been obtained from careful numerical simulation. Physical insights of these rich fluidic phenomena are described using well-resolved velocity vectors in the wall jet and upwash.

Robotic volumetric PIV of a full-scale cyclist

A novel approach to the measurement of large-scale complex aerodynamic flows is presented, based on the combination of coaxial volumetric velocimetry and robotics. Volumetric flow field measurements are obtained to determine the time-averaged properties of the velocity field developing around a three-dimensional full-scale reproduction of a professional cyclist. The working principles of robotic volumetric PIV are discussed on the basis of its main components: helium-filled soap bubbles as tracers; the compact coaxial volumetric velocimeter; a collaborative 6 degrees of freedom robot arm; particle image analysis based on Shake-the-Box algorithm and ensemble statistics to yield data on a Cartesian mesh in the physical domain. The spatial range covered by the robotic velocimeter and its aerodynamic invasiveness are characterised. The system has the potential to perform volumetric measurements in a domain of several cubic metres. The application to the very complex geometry of a full-scale cyclist in time-trial position is performed in a large aerodynamic wind tunnel at a flow speed of 14 m/s. The flow velocity in the near field of the cyclist body is gathered through 450 independent views encompassing a measurement volume of approximately 2 m3. The measurements include hidden regions between the arms and the legs, otherwise very difficult to access by conventional planar or tomographic PIV. The time-averaged velocity field depicts the main flow topology in terms of stagnation points and lines, separation and reattachment lines, trailing vortices and free shear layers. The wall boundary layers developing on the body surface hide below the level resolvable by the present measurements.

Aerodynamics of a stay cable with helical fillets - Part I: Stability and load characteristics

The aerodynamic behaviour of a bridge stay cable with helical fillets in smooth flow at high Reynolds numbers is presented in this paper. The cable response and related sectional load characteristics were studied experimentally on a 1:1 scale cable section model. The studies showed that a cable with helical fillets inclined 60° to the flow could experience large amplitude wind induced vibrations and that the occurrence of vibrations were highly dependent on cable surface irregularities. The ambition is not to explain fully the excitation mechanism, but to present global and local influences of the helical fillets on the flow field. It was revealed that the flow field around the cable shifted between semi-stable transition states which took place when the transition from laminar to turbulent flow propagated from the free shear layers to the boundary layer. The transitions would form locally and spread along the cable axis. The helical fillet appeared to dominate the local flow structures when located at an angular position between 40° and 130° from the stagnation region. In the stagnation and base regions, the surface irregularities appeared to dominate. Furthermore, the helical fillets displaced the mean stagnation line. The application of quasi-steady theory with the measurement data available appeared not to be able to explain the vibrations.

Numerical algorithms for infinite swept wing ice accretion

A method to simulate ice accretion on swept wings using a two-dimensional Navier-Stokes airflow solver, an Eulerian droplets field formulation and a PDE based thermodynamic model is presented. The current approach, called 2.5D in this paper, is developed by applying a rotation of the system of coordinates to allow simulations on a cut normal to the leading edge. The crossflow velocity component in the simulation plane is computed with the third momentum equation simplified by assuming null derivatives in the spanwise direction. The consistency of the ice accretion software, NSCODE-ICE, is first verified by a grid convergence study on 2D icing cases and an icing layers convergence study on 2D and 2.5D icing simulations. The validation of the approach is performed on an unswept two-dimensional glaze ice case and on a rime ice case. The current 2.5D approach is then validated on an infinite MS-317 swept wing and compared to results from usual semi-empirical infinite swept wing corrections. The new approach succeeds to model the stagnation line where other correction methods fail, leading to a better representation of the convective heat transfer in this area.

Development of a Radiative Heating Margin Policy for Lunar Return Missions

The present paper discusses the development of a margin policy for radiative heating during lunar return Earth reentry. The approach starts with stagnation line radiance predictions, for which significant validation data are available, and follows a mathematical formalism to translate the uncertainty in radiance prediction to an uncertainty in radiative heating. The analysis accounts for uncertainties in equilibrium and nonequilibrium radiance, angular integration, boundary-layer absorption, and flowfield–radiation coupling. Uncertainties based on parametric analyses are then reduced through Bayesian inference against experimental data. Terms are introduced to account for the neglect of ablation products and trace air species. The impact is then assessed through analysis of candidate entry trajectories. The major contributors to margin are uncertainty in equilibrium radiation parameters, nonequilibrium radiation, and neglect of trace species.

MMS Observations of Reconnection at Dayside Magnetopause Crossings During Transitions of the Solar Wind to Sub‐Alfvénic Flow

AbstractWe present MMS observations during two dayside magnetopause crossings under hitherto unexamined conditions: (i) when the bow shock is weakening and the solar wind transitioning to sub‐Alfvénic flow and (ii) when it is reforming. Interplanetary conditions consist of a magnetic cloud with (i) a strong B (∼20 nT) pointing south and (ii) a density profile with episodic decreases to values of ∼0.3 cm−3 followed by moderate recovery. During the crossings the magnetosheath magnetic field is stronger than the magnetosphere field by a factor of ∼2.2. As a result, during the outbound crossing through the ion diffusion region, MMS observed an inversion of the relative positions of the X and stagnation (S) lines from that typically the case: the S line was closer to the magnetosheath side. The S line appears in the form of a slow expansion fan near which most of the energy dissipation is taking place. While in the magnetosphere between the crossings, MMS observed strong field and flow perturbations, which we argue to be due to kinetic Alfvén waves. During the reconnection interval, whistler mode waves generated by an electron temperature anisotropy (Te⊥>Te∥) were observed. Another aim of the paper is to distinguish bow shock‐induced field and flow perturbations from reconnection‐related signatures. The high‐resolution MMS data together with 2‐D hybrid simulations of bow shock dynamics helped us to distinguish between the two sources. We show examples of bow shock‐related effects (such as heating) and reconnection effects such as accelerated flows satisfying the Walén relation.

Influence of turbine blade leading edge shape on film cooling with cylindrical holes

Influence of turbine blade leading edge shape, gill film, and coolant-to-mainstream density ratio and blowing ratio on film cooling with cylindrical holes has been experimentally studied using pressure sensitive paint (PSP) technique. Three leading edge models are selected including a semi cylinder of radius R=38.1mm, elliptical leading edges of major radius 1.5R & 2.0R with an after body. Each leading edge model has three rows of film cooling holes with 15 holes each at fixed pitch of 4 hole-diameter and located along the stagnation line (0°) and at ±30°, respectively. Additional two rows of gill holes are located at ±60° (measured from inside surface). Internal impingement cooling geometry has been used while keeping the impingement hole plate at fixed distance of 31.7mm from the stagnation line in all three leading edge models. Two configurations, with gill film holes ON and OFF are tested separately and the effects of coolant-to-mainstream density ratios (DR=1.0, 1.5 and 2.0) with three different blowing ratios (M=0.5, 1.0 and 1.5) are investigated. Experiments were conducted in a suction type low-speed wind-tunnel facility at Reynolds number of 102,446 based on the mainstream velocity and leading edge diameter. The mainstream turbulence intensity near the leading edge model is about 7%. Results indicate that 1.5R leading edge model has relatively better performance over others and gill film holes benefit to achieve improved coverage with higher overall film effectiveness. Additionally, to understand the flow physics, computational simulations for 1.0R leading edge model for DR=1.5 and 2.0 at M=1.0 are also performed using realizable k-ɛ turbulence model for both gill film holes ON and OFF.

Local heat transfer for jet impingement onto a concave surface including injection nozzle length to diameter and curvature ratio effects

The effect of jet nozzle length to diameter ratio on local heat transfer coefficient measurements for a row of circular jets impinging onto a concave surface for varying target spacing are reported here. The nozzle length to diameter ratio (L/d) and the nozzle to target spacing (H/d) were varied from 0.2 to 6 and 0.67 to 8 respectively. Three curvature ratios, defined as the ratio of jet diameter to target surface diameter (d/D), equal to 0.1, 0.2 and 0.3 were studied and the jet to jet pitch to diameter ratio (P/d) was kept constant at 4.0. The Reynolds number was varied between 10,000 and 50,000 and wall static pressures for some cases were measured for obtaining a better understanding of the heat transfer coefficient variations.Higher stagnation zone Nusselt numbers were observed for the jet nozzles with small L/d at small H/d values whereas at larger H/d values nozzle length was observed to affect the data only marginally. The difference between Nusselt number values, between H/d=2 and H/d=8, was observed to progressively reduce with increasing L/d ratio and this was true for both the local stagnation point as well as the spanwise averaged stagnation line values. The maximum local Nusselt number values were observed to shift from the geometric impingement location to nearby locations for very small nozzle diameter to target distance ratios (H/d≤1) for larger curvature ratios. A constant heat transfer impingement area with constant pumping power criterion is presented to compare the performance of the different configurations studied. The longer nozzle lengths and smaller curvature ratios are observed to perform better based on this criterion. A correlation is presented for the overall averaged Nusselt number, with a validity within the parameter range studied, with a ±10% error band.

Streaming from the Equator of a Drop in an External Electric Field.

Tip streaming generates micron- and submicron-sized droplets when a thin thread pulled from the pointy end of a drop disintegrates. Here, we report streaming from the equator of a drop placed in a uniform electric field. The instability generates concentric fluid rings encircling the drop, which break up to form an array of microdroplets in the equatorial plane. We show that the streaming results from an interfacial instability at the stagnation line of the electrohydrodynamic flow, which creates a sharp edge. The flow draws from the equator a thin sheet which destabilizes and sheds fluid cylinders. This streaming phenomenon provides a new route for generating monodisperse microemulsions.

Simulations of Carbon-Dioxide Equilibrium Infrared Radiation Measurements

This paper presents the simulations of equilibrium infrared radiation measurements. Transmission measurements and line-of-sight intensity measurements from microwave plasma torches and shock tubes were reviewed and used to assess the accuracy of the available spectral databases HITEMP and CDSD for equilibrium conditions relevant to Mars atmosphere entry flows. Various test cases were selected to quantify the accuracy and the computing time of the databases. Spectral radiative heat fluxes along lines of sight of both a typical Mars entry stagnation line and wake flows were computed. The influence of the database and the effect of the pressure as well as the temperature profiles on the spectral radiative heat flux are discussed.

Experimentally Measured Effects of Incidence Angle on the Adiabatic and Overall Effectiveness of a Fully Cooled Turbine Airfoil With Shaped Showerhead Holes

Manufacturing and assembly variation can lead to shifts in the inlet flow incidence angles of a rotating turbine airfoil row. Understanding the sensitivity of the adiabatic film cooling effectiveness to a range of inlet conditions is necessary to verify the robustness of a cooling design. In order to investigate the effects of inlet flow incidence angles, adiabatic and overall effectiveness data were measured in a low speed linear cascade at 0 deg and 10 deg of the designed operating condition. Tests were completed at an inlet Reynolds number of Re = 120,000 and a turbulence intensity of Tu = 5% at the leading edge of the test article. Particle image velocimetry was used to verify the incident flow angle for each angle studied. The test section was first adjusted so that the pressure distribution and stagnation line of the airfoil matched those predicted by an aerodynamic computational fluid dynamics (CFD) model. IR thermography was then used to measure the adiabatic effectiveness levels of the fully cooled airfoil model with nine rows of shaped holes of varying construction and feed delivery. Measurements were taken over a range of blowing ratios and at a density ratio of DR = 1.23. This process was repeated for the two incidence angles measured, while the inlet pressure to the airfoil model was held constant for these incidence angle changes. Differences in laterally adiabatic effectiveness across the airfoil model were most evident in the showerhead, with changes as large as 0.2. The effect persisted most strongly at s/D = ±35 downstream of the stagnation row of holes, but was visible over the whole viewable area of 160 s/D. The effect was due to the stagnation line affecting the film at the showerhead row. Due to this effect, the showerhead was investigated in detail, including the effects of the stagnation line shift as well as the influence of the incidence angle on the overall effectiveness of the showerhead region. It was found that the stagnation line has the tendency to dramatically increase the near-hole adiabatic effectiveness levels when positioned within the breakout footprint of the hole. The effect persisted for the overall effectiveness study, since the hole spacing for this particular configuration was wide enough that the through hole convection was not completely dominant. This is the first study to present measured effectiveness values over both the pressure- and suction-side surfaces of a fully cooled airfoil for appreciably off-nominal incidence angles as well as examine adiabatic and overall effectiveness levels for a conical stagnation row of holes.

PIV measurements in the near wakes of hollow cylinders with holes

The wake flows behind fixed, hollow, rigid circular cylinders with two rows of holes connecting the front and rear stagnation lines were investigated using particle image velocimetry (PIV) for various combinations of three hole diameters, d = 0.1D, 0.15D, and 0.20D, six hole-to-hole distances, l = 2d, 3d, 4d, 5d, 6d, and 7d, and ten angles of incidence (α), from 0° to 45° in steps of 5°, at a Reynolds number of Re = 6,900. Time-averaged velocity distributions, instantaneous and time-averaged vorticity patterns, time-averaged streamline topology, and hot spots of turbulent kinetic energy occurred through the interaction of shear layers from the models were presented to show how the wake flow was modified by the presence of the self-issuing jets with various momentums emanating from the downstream holes. In general, as hole diameter which is directly related to jet momentum increased, the values of time-averaged wake characteristics (length of time-averaged recirculation region, vortex formation length, length of shear layers, and gap between the shear layers) increased. Irrespective to d and l tested, the values of the vortex formation length of the models are greater than that of the cylinder without hole (reference model). That is, vortex formation process was shifted downstream by aid of jets. It was found that time-averaged wake characteristics were very sensitive to α. As α increased, the variation of these characteristics can be modeled by exponential decay functions. The effect of l on the three-dimensional vortex shedding patterns in the near wake of the models was also discussed.

New chemical-DSMC method in numerical simulation of axisymmetric rarefied reactive flow

The modified quantum kinetic (MQK) chemical reaction model introduced by Zakeri et al. is developed for applicable cases in axisymmetric reactive rarefied gas flows using the direct simulation Monte Carlo (DSMC) method. Although, the MQK chemical model uses some modifications in the quantum kinetic (QK) method, it also employs the general soft sphere collision model and Stockmayer potential function to properly select the collision pairs in the DSMC algorithm and capture both the attraction and repulsion intermolecular forces in rarefied gas flows. For assessment of the presented model in the simulation of more complex and applicable reacting flows, first, the air dissociation is studied in a single cell for equilibrium and non-equilibrium conditions. The MQK results agree well with the analytical and experimental data and they accurately predict the characteristics of the rarefied flowfield with chemical reaction. To investigate accuracy of the MQK chemical model in the simulation of the axisymmetric flow, air dissociation is also assessed in an axial hypersonic flow around two geometries, the sphere as a benchmark case and the blunt body (STS-2) as an applicable test case. The computed results including the transient, rotational and vibrational temperatures, species concentration in the stagnation line, and also the heat flux and pressure coefficient on the surface are compared with those of the other chemical methods like the QK and total collision energy (TCE) models and available analytical and experimental data. Generally, the MQK chemical model properly simulates the chemical reactions and predicts flowfield characteristics more accurate rather than the typical QK model. Although in some cases, results of the MQK approaches match with those of the TCE method, the main point is that the MQK does not need any experimental data or unrealistic assumption of specular boundary condition as used in the TCE method. Another advantage of the MQK model is the significant reduction of computational cost rather than the QK chemical model to reach the same accuracy because of applying more proper collision model and consequently, decrease of the particles collision number.

Experimental Investigation of Film Cooling Performance for a New Shaped Hole at the Leading Edge

An experimental investigation has been performed to study the film cooling performance of a smooth expansion exit at the leading edge of a gas turbine vane. A two-dimensional cascade has been employed to measure the cooling performance of the proposed expansion using the transient Thermochromatic Liquid Crystal technique. One row of cylindrical holes, located on the stagnation line, is investigated with two expansion levels, 2d and 4d, in addition to the standard hole. The air is injected at 90o and 60o inclination angle relative to the vane surface at four blowing ratios ranging from 1 to 2 at a 0.9 density ratio. The Mach number and the Reynolds number based on the cascade exit velocity and the axial chord are 0.23 and 1.4E5, respectively. The detailed local heat transfer coefficient over both the pressure side and the suction side are presented in addition to the lateral-averaged normalized heat transfer coefficient. The proposed expansion provides a lower heat transfer coefficient compared with the standard cylindrical hole over the investigated blowing ratios. Combining the heat transfer coefficient with the corresponding cooling effectiveness, previously presented, the smooth expansion shows a significant reduction in the heat load with more uniform distribution of the coolant over the leading-edge region. The strong confrontation between the coolant jet and the mainstream, in case of 90o injection, yields a strong dispersion of the coolant with higher heat transfer coefficient and high thermal load over the vane surface.

Numerical Study of a Three Dimensional Interaction between two bow Shock Waves and the Aerodynamic Heating on a Wedge Shaped Nose Cone

This paper presents a numerical investigation on the three-dimensional interaction between two bow shock waves in two environments, i.e. ground high-enthalpy wind tunnel test and real space flight, using Fluent 15.0. The first bow shock wave, also called induced shock wave, which is generated by the leading edge of a hypersonic vehicle. The other bow shock wave can be deemed objective shock wave, which is generated by the cowl clip of hypersonic inlet, and in this paper the inlet is represented by a wedge shaped nose cone. The interaction performances including flow field structures, aerodynamic pressure and heating are analyzed and compared between the ground test and the real space flight. Through the analysis and comparison, we can find the following important phenomena: 1) Three-dimensional complicated flow structures appear in both cases, but only in the real space flight condition, a local two-dimensional type IV interaction appears; 2) The heat flux and pressure in the interaction region are much larger than those in the no-interaction region in both cases, but the peak values of the heat flux and pressure in real space flight are smaller than those in ground test. 3) The interaction region on the objective surface are different in the two cases, and there is a peak value displacement of 3 mm along the stagnation line.

Comparison of RANS and Detached Eddy Simulation Modeling Against Measurements of Leading Edge Film Cooling on a First-Stage Vane

The performance of a showerhead arrangement of film cooling in the leading edge region of a first-stage nozzle guide vane was experimentally and numerically evaluated. A six-vane linear cascade was tested at an isentropic exit Mach number of Ma2s = 0.42, with a high inlet turbulence intensity level of 9%. The showerhead cooling scheme consists of four staggered rows of cylindrical holes evenly distributed around the stagnation line, angled at 45 deg toward the tip. The blowing ratios tested are BR = 2.0, 3.0, and 4.0. Adiabatic film cooling effectiveness distributions on the vane surface around the leading edge region were measured by means of thermochromic liquid crystals (TLC) technique. Since the experimental contours of adiabatic effectiveness showed that there is no periodicity across the span, the computational fluid dynamics (CFD) calculations were conducted by simulating the whole vane. Within the Reynolds-averaged Navier–Stokes (RANS) framework, the very widely used realizable k–ε (Rke) and the shear stress transport k–ω (SST) turbulence models were chosen for simulating the effect of the BR on the surface distribution of adiabatic effectiveness. The turbulence model which provided the most accurate steady prediction, i.e., Rke, was selected for running detached eddy simulation (DES) at the intermediate value of BR = 3. Fluctuations of the local temperature were computed by DES, due to the vortex structures within the shear layers between the main flow and the coolant jets. Moreover, mixing was enhanced both in the wall-normal and spanwise directions, compared to RANS modeling. DES roughly halved the prediction error of laterally averaged film cooling effectiveness on the suction side of the leading edge. However, neither DES nor RANS provided the expected decay of effectiveness progressing downstream along the pressure side, with 15% overestimation of ηav at s/C = 0.2.