Cylinder Span Research Articles

Spanwise Characteristics of Flow Crossing a Yawed Circular Cylinder of Finite Length

The spanwise characteristics of flow passing a yawed finite circular cylinder are numerical investigated at the yaw angle of 30°, aspect ratio of 9 and Reynolds number of 3900 using Large Eddy Simulation. The wake vortical structure and streamlines manifest that the regular Karman vortex street breaks down and there exists axial flow along the cylinder axis. To get further insight into the spanwise characteristics, the cylinder is virtually divided into nine equal-spaced sections along the cylinder span, and the drag and lift force coefficients of each section are monitored. By comparing the drag coefficients of these nine cylinder sections, it is found that the anti-clockwise torque is imposed on the cylinder. Furthermore, the FFT analyses of these nine fluctuating lift coefficients are carried out to reveal the characteristics in the frequency domain. It is shown that the nine spectra demonstrate different behaviours, by which the wake vortical structure is identified spanwise as three regions, two end-plate regions and the midspan region. In the downstream end-plate region, the vortex-shedding is well organized, whereas in the upstream end-plate region the wake vortex structure manifests itself stronger three-dimensional and severely irregular. And in the midspan region, the peak of frequency spectra is broadband and the regular Karman vortex street is not yet noticeable to identify.

A review of flow-induced noise from finite wall-mounted cylinders

This paper reviews previous studies on the flow around and flow-induced noise produced by a finite wall-mounted cylinder (FWMC) of circular and square cross section. The flow around a square FWMC is somewhat understood. Conversely, the flow around a circular FWMC is not well understood, particularly because of the phenomenon of spanwise cellular shedding. The effect of the aspect ratio (the ratio of cylinder span to diameter) on the near wake structure has been most extensively studied in the literature. However, the effect of the height of the incoming boundary layer on the near wake structure has not been comprehensively investigated and is therefore unclear, despite it being identified as a major influencing parameter on the development of the wake. Similarly, only a few studies have been conducted on the flow-induced noise of FWMCs and there is a general lack of data on the flow-induced noise characteristics and mechanisms of an FWMCs in cross flow. Nevertheless, the amalgamation of the limited data set has led to several noise generation hypotheses: (1) lower frequency tonal noise generation is due to the development of separate structures along the span of both circular and square FWMCs and (2) that increasing the boundary layer thickness will promote tonal noise generation.

Three-dimensional numerical simulation of vortex-induced vibration of an elastically mounted rigid circular cylinder in steady current

Vortex-induced vibration (VIV) of an elastically mounted rigid circular cylinder in steady current is investigated by solving the three-dimensional Navier–Stokes equations. The cylinder is allowed to vibrate only in the cross-flow direction. The aim of this study is to investigate the variation of the vortex shedding flow in the axial direction of the cylinder and to study the transition of the flow from two-dimensional (2D) to three-dimensional (3D) for VIV of a cylinder. Simulations are carried out for a constant mass ratio of 2, the Reynolds numbers ranging from 150 to 1000 and the reduced velocities ranging from 2 to 12. The three-dimensionality of the flow is found to be the strongest in the upper branch of the VIV response and weakest in the initial branch. The 2S and 2P vortex shedding modes are found to coexist along the cylinder span in the upper branch, leading to strong variations of the lift coefficient in the axial direction of the cylinder. The difference between the flow transition from 2D to 3D in the VIV lock-in regime and that in the wake of a stationary cylinder is identified. The transition mode B found in the wake of a stationary cylinder is also found in the wake of a vibrating cylinder. The critical Reynolds number for flow transition from 2D to 3D of a cylinder undergoing cross-flow VIV at a reduced velocity of 6 is found to be greater than that for a stationary cylinder. For a constant reduced velocity of 6, the wake flow changes from 2D to 3D as the Reynolds number is increased from 250 to 300. Some 2D numerical simulations are performed and it is found that the 2D Navier–Stokes (NS) equations are not able to predict the VIV in the turbulent flow regime, while the 2D Reynolds-averaged Navier–Stokes (RANS) equations improve the results.

Coupled delayed-detached-eddy simulation and structural vibration of a self-oscillating cylinder due to vortex-shedding

The flow past a rigid-fixed cylinder and a self-oscillating cylinder is simulated at Re=5000. The finite-volume based CFD package OpenFOAM is used for flow computations for a rigid-fixed cylinder. Extensive mesh convergence and time-step studies are conducted for a cylinder span of 2D (twice the diameter). Spanwise-pressure correlations and spectral calculations are conducted using longer cylinder span lengths: 4D, 8D and 16D. As the cylinder span size increases, better spanwise correlations are obtained. For a self-oscillating cylinder, the numerical approach that tightly couples DDES and FEA based on a fixed point iteration is used to predict the amplitude response and drag in a lock-in condition. The results of the rigid-fixed and self-oscillating cylinder computations compare favorably with experimental data.

Vortex-induced vibration of a circular cylinder of finite length

Vortex-induced vibration (VIV) of a rigid circular cylinder of finite length subject to uniform steady flow is investigated numerically. The study is focused on the effect of the free end on the response of the cylinder. The vibration of the cylinder is confined only in the cross-flow direction. Three-dimensional Navier-Stokes equations are solved by the Petrov-Galerkin finite element method and the equation of the motion is solved for the cylinder displacement. Simulations are conducted for a constant mass ratio of 2, a constant Reynolds number of 300 and cylinder length to diameter ratios of L/D = 1, 2, 5 10, and 20. It is found that the vortex shedding in the wake of a fixed cylinder is suppressed if the cylinder length is less than 2 cylinder diameters. However, if the cylinder is allowed to vibrate, VIV happens at L/D = 1 and 2 and the response amplitudes at these two cylinder lengths are comparable with that of a 2D-cylinder. The vortices that are shed from a short cylinder of L/D = 1 and 2 are found to be generated from the free-end of the cylinder and convected toward the top end of the cylinder by the upwash velocity. They are found to be nearly perpendicular to the cylinder span. The wake flow in a vibrating cylinder with L/D greater than 5 includes the vortex shedding flow at the top part of the cylinder and the end-induced vortex shedding near the free-end of the cylinder. The phase difference between the sectional lift coefficient and the vibration displacement near the free-end of the cylinder changes from 0° to 180° at higher reduced velocity than that near the top end. Strong variation of the flow along the cylinder span occurs at reduced velocities where the lift coefficient near the free-end and that near the top end are in anti-phase with each other.

The appearance of two lock-in states in the vortex flow around an in-line forced oscillating circular cylinder

In this study, the flow features of vortex shedding from a circular cylinder forced-oscillating in the in-line direction were investigated by use of flow visualization experiment and numerical simulation at the Reynolds number Re =620, with varied amplitude ratio and varied frequency ratio. As a result of the experiments, it was found that although the flow structure around the circular cylinder is two-dimensional in the lock-in state of simultaneous vortex shedding, the large scale three-dimensional instability is observed in the lock-in state of alternate vortex shedding through a time lag in the boundary layer separation along the cylinder span. As a result of calculations, two typical flow patterns of the lock-in were shown, and it was confirmed that the calculated flow patterns were in reasonable agreement with previous experimental results. The fluid force act on the oscillating cylinder was investigated. It was clarified that the amplitude of the lift coefficient was larger than the amplitude of the drag coefficient in the lock-in of alternate vortex shedding, and the amplitude of the drag coefficient was larger than the amplitude of the lift coefficient in the lock-in of simultaneous vortex shedding. When the amplitude ratio 2 a/d grows, this tendency becomes remarkable.

Aerodynamic Force of a Cantilevered Cylinder in Uniform Flow and Turbulent Boundary Layer

The aerodynamic force and pressure distribution on a cantilevered cylinder with aspect ratio of 5 mounted in smooth uniform oncoming flow and turbulent boundary layer have been experimentally investigated. The tested Reynolds number ranges from 0.64×105 to 5.81×105, covering subcritical, critical and supercritical regimes. The results indicate that the aerodynamic drag of a cantilevered cylinder is smaller that that of 2D cylinder. The drag differs significantly along cylinder span because of the three dimensionality of the flow. The presence of turbulent boundary layer makes cylinder back pressure more uniform along cylinder span relative to that in uniform flow. Transition from subcritical to critical regime occurs earlier near cylinder free end in uniform flow, while this behavior disappears with the presence of turbulent boundary layer.

Vortex Shedding in a Tandem Circular Cylinder System With a Yawed Downstream Cylinder

This investigation examines the flow produced by a tandem cylinder system with the downstream cylinder yawed to the mean flow direction. The yaw angle was varied from α=90deg (two parallel tandem cylinders) to α=60deg; this has the effect of varying the local spacing ratio between the cylinders. Fluctuating pressure and hot-wire measurements were used to determine the vortex-shedding frequencies and flow regimes produced by this previously uninvestigated flow. The results showed that the frequency and magnitude of the vortex shedding varies along the cylinder span depending on the local spacing ratio between the cylinders. In all cases the vortex-shedding frequency observed on the front cylinder had the same shedding frequency as the rear cylinder. In general, at small local spacing ratios the cylinders behaved as a single large body with the shear layers separating from the upstream cylinder and attaching on the downstream cylinder, this caused a correspondingly large, low frequency wake. At other positions where the local span of the tandem cylinder system was larger, small-scale vortices began to form in the gap between the cylinders, which in turn increased the vortex-shedding frequency. At the largest spacings, classical vortex shedding persisted in the gap formed between the cylinders, and both cylinders shed vortices as separate bodies with shedding frequencies typical of single cylinders. At certain local spacing ratios two distinct vortex-shedding frequencies occurred indicating that there was some overlap in these flow regimes.

Quantitative numerical analysis of flow past a circular cylinder at Reynolds number between 50 and 200

Results of numerical simulations are presented for flow past a stationary circular cylinder at low Reynolds numbers (Re=50–200). The simulations were carried out using a finite-volume code employing a fractional step method with second-order accuracy in both space and time. A sensitivity study on numerical parameters concerning the domain size, grid independence and time step resolution was carried out in detail for Re=100. Global time-averaged results on force coefficients, non-dimensional velocities and pressures, including their corresponding r.m.s. values, as well as various quantities related to the separation and vortex shedding characteristics are presented. A non-monotonous streamwise velocity recovery in the intermediate wake is observed for Re>50, a phenomenon that has been grossly overlooked in the past. There are two plateaus along the wake centerline, in particular for Re=200. The first, which is the most distinct, ranges from about x=9 to x=16 at a wake deficit velocity of 0.38, x being counted in diameters behind the cylinder axis; the second one appears from x=25 to x=28 at a wake deficit velocity of 0.54. This phenomenon seems to be related to an associated change-over in the orientation of the von Kármán vortices and the merging trends, especially for Re=200 beyond x=25, as observed from instantaneous vorticity fields. Three-dimensional simulations using spanwise lengths of 10 and 12 (diameters) were carried out at Re=200. After a long initial phase with regular three-dimensional mode A flow features increasing very slowly in amplitude, the flow went into a state with distinct pulsating forces acting on the cylinder, the pulsations being seemingly randomly localized across the cylinder span. In this second, much more chaotic, flow state, the time-averaged results were in agreement with previous experiments and with parts of previous numerical studies.

Three-dimensional transition of vortex shedding flow around a circular cylinder at right and oblique attacks

Vortex shedding from an inclined circular cylinder at low values of Reynolds number (Re) is investigated numerically. The aim of the study is to investigate the effect of cylinder oblique angle on the transition from two-dimensionality (2D) to three-dimensionality (3D) of the wake flow. The Navier-Stokes equations are solved by the Petrov-Galerkin finite element method for Reynolds numbers ranging from 100 to 1000 and the flow attack angles of α = 0° and 45°. For the right attack angle case (α = 0°), the predicted wavy spanwise vortices in the early stage of the transition mode A, the vortex dislocation in the late stage of the transition mode A and the streamwise-vortex dominant wake flow structure in the transition mode B are found to agree well with independent experimental observations and measurements. The transition from 2D to 3D at α = 45° was found distinctively different from that at α = 0°. For α = 45°, no clear-cut transition modes are observed. The wake is characterized by wavy spanwise vortices close to the lower boundary of the transition Reynolds number regime, which are similar to those in the early stage of the transition mode A at α = 0°. The vortex-dislocation in the transition mode A was not observed at α = 45°. It appears that the fluid flow in the spanwise direction in the primary vortices at α = 45° does not allow the instability to sustain at a specific spanwise location and trigger the vortex dislocation. Although the wake flow structure is different, the variation of the normal Strouhal number with the normal Reynolds number (both based on the velocity component perpendicular to the cylinder span) at α = 45° is close to that at α = 0° in the transitional Reynolds number regime. The root mean square of the lift coefficient normalized by the velocity component perpendicular to the axial direction of the cylinder at α = 45° is about 20% to 25% larger than that at α = 0° in the Reynolds number regime between 250 and 500.

A Study of Slender Bluff-Body Reacting Wakes Formed by Concurrent or Countercurrent Fuel Injection

The work presents an investigation of turbulent propane flames stabilized by planar injection across the span of a square cylinder, either from its leading face against the approach flow or directly into its vortex formation region. The non-premixed or partially premixed reacting wakes were studied by regulating the fuel injection level and position. Turbulent velocities, temperatures, CH*, flame images, and exhaust emissions were measured using laser velocimetry, digitally compensated thermocouples, chemiluminescence imaging, and gas analysis. Lean and ultra-lean fuel/air velocity ratios of 0.36 and 0.23 were investigated under concurrent and countercurrent injection at a Reynolds number, based on the square burner diameter, of 5700. Large eddy simulations were undertaken using the dynamic Smagorinsky model, the eddy dissipation concept, and an 11-step global mechanism for propane combustion and NOx. The methodology helped to elucidate some aspects regarding the interaction of the flame front with the vortex formation region, the impact of heat release on wake development, and the flame behavior as lean blow-off (LBO) was approached, under both forms of fuel injection. Differences between the partially premixed planar wake and other types of non-premixed or fully premixed configurations were also exposed and discussed. At the initial stages of fuel reduction toward blow-off, the simulations suggested a more efficient stabilization of the flanking reacting fronts within the side vortices of the counterinjected square burner by comparison to axisymmetric counterparts. However, as the two reactive layers were progressively retracted, the large scale asymmetric vortex shedding was reinstated at the flame trailing edges and had a detrimental effect on overall stability leading to a more rapid approach to LBO in the final stages.

Numerical Experimental Research on the Hydrodynamic Performance of Flow around a Three Dimensional Circular Cylinder

Using the CFX software and the Large Eddy Simulaion (LES) method, this paper numerically simulates the hydrodynamic characteristics of the flow around a 3d circular cylinder at high Reynolds number (Re=5.6×103, 2.8×104, 1.1×105). The numerical simulation focuses on investigating the vortex shedding angle, the characteristics of the vortex shedding and the vortex tube, the base pressure, the static and the fluctuating drag and lift. The result of calculation shows that the forces of every section along the span of cylinder are symmetrical with respect to the middle section. Moreover the flow around the cylinder obviously appears three dimensional characteristics at high Reynolds number.

Effects of a geometrical surface disturbance on flow past a circular cylinder: a large-scale spanwise wire

Flow control induced by a single wire that is attached on the outer surface and parallel to the span of a stationary circular cylinder is investigated experimentally. The Reynolds number has a value of 10 000 and the wire diameter is nearly two orders of magnitude smaller than the cylinder diameter, while being larger than the thickness of the unperturbed boundary layer forming around the cylinder. A technique of high-image-density particle image velocimetry is used to characterize mean and unsteady structures of the separating shear layer and the near wake. Only one of the shear layers is directly perturbed by the surface wire. This disturbance, however, has important global consequences over the entire near wake, provided that the wire is located within a certain range of angular positions with respect to the approach flow. Over this range, there are two angles that can be defined as critical on the basis of the streamwise extent of the near-wake structure. In a simplified sense, these critical angles are associated with significant extension and contraction of the near wake, relative to the wake in the absence of the effect of a surface disturbance. The critical angle of the wire that yields the most significant extension of the near wake is also found to lead to bistable oscillations of the separating shear layer at irregular time intervals, much longer than the time scale associated with the classical Kármán vortex shedding. The foregoing two critical states of extension and contraction of the near wake are, respectively, linked to attenuation or enhancement of the Kármán instability. Moreover, the onset of the shear-layer instability, Reynolds stress, Strouhal number and the transverse extent of shear-layer flapping are all shown to depend on the angular position of the wire within the defined range of angles.

Transition to turbulence in the separated shear layers of yawed circular cylinders

Spatial and temporal resolution of transition to turbulence inside the free-shear layers of two yawed circular cylinders is the subject of the present investigation. These physics were resolved using the large-eddy simulation (LES) methodology. An O-type grid was implemented such that the spatial scales of the LES computation fully resolved the energy range physics of the shear layers at Reynolds number Re D = 8000 based on the cylinder diameter. The two test cases modeled the cylinder span skewed at angles 45° and 60° from the horizontal axis. Observations revealed the same transition process as the normal cross-flow state. Soon after separation, Tollmien–Schlichting disturbances were predicted that evolved into Kelvin–Helmholtz (K–H) eddies before absorption by the large-scale Karman-type vortices. These eddies defaulted to a spanwise wavy pattern similar to a normal cross-flow due to their three-dimensional instability. No mixed modes were found between the K–H (Bloor) and Strouhal frequencies. The effect of yaw angle shortened the transition process. As a result, peak turbulence levels inside the wake formation zone approach the downstream cylinder periphery. In addition, the dimensionless frequencies of the K–H eddies lie above the normal cross-flow relationship as formulated by Bloor (1964). Disparity between the yawed and normal cross-flow states was further emphasized by the shear-layer transition characteristics. Although each property displayed the expected exponential growth during transition to turbulence, their dimensionless form was miss-aligned with those of the normal cross-flow case. Based on the present evidence, additional simulations (and/or experimental measurements) are necessary to form conclusive arguments regarding the expected behavior of the transition characteristics within the free-shear layers of yawed circular cylinders.

The Spanwise Dependence of Vortex-Shedding From Yawed Circular Cylinders

Simultaneous measurements of the fluctuating wall pressure along the cylinder span were used to examine the spanwise characteristics of the vortex-shedding for yaw angles varying from α=60 deg to α=90 deg. The Reynolds number based on the diameter of the cylinder was 56,100. The results indicate that yawing the cylinder to the mean flow direction causes the vortex-shedding in the wake to become more disorderly. This disorder is initiated at the upstream end of the cylinder and results in a rapid decrease in correlation length, from 3.3D for α=90 deg to 1.1D for α=60 deg. The commonly used independence principle was shown to predict the vortex-shedding frequency reasonably well along the entire cylinder span for α>70 deg, but did not work as well for α=60 deg.

Induced parallel vortex shedding from a circular cylinder at Re of O(10 4) by using the cylinder end suction technique

In the present work, the objective is to attempt to induce parallel vortex shedding at a moderately high Reynolds number (=1.578 × 10 4) by using the cylinder end suction method, and measure the associated aerodynamic parameters. We first measured the aerodynamic parameters of a single circular cylinder without end suction, and showed that the quantities measured are in good agreement with equivalent data in the published literature. Next, by using different amount of end suction which resulted in increasing the cylinder end velocity by 1%, 2% and 2.5%, we were able to show that the above corresponded to the situation of under suction, optimal suction and over suction, respectively. With optimal suction, we demonstrated that the end suction method works at Re = 1.578 × 10 4. The shape of the primary vortex shed became straighter than when there is no end suction, and parameters like cylinder surface pressure distribution, drag force per unit span, as well as vortex shedding frequency all showed negligible spanwise variation. Further careful analyses showed that when compared to the naturally existing curved vortex shedding, with parallel vortex shedding the mid-span drag per unit span became slightly smaller, but the drag averaged over the cylinder span became slightly larger. For cylinder surface pressure, it was found that cylinder end effects mainly influenced the surface pressure in the angular ranges −180° ⩽ β < −60° and 60° < β ⩽ 180°. Without end suction, the cylinder surface pressure in the above ranges was found to increase (become less negative) slightly with | z/ d|, but such increase disappeared when optimal end suction was applied, and the cylinder surface pressure distribution became spanwise location independent. As for the vortex shedding frequency (Strouhal number), although the Strouhal number showed spanwise variation when there is no end suction and negligible spanwise variation when optimal suction was applied, the difference between the spanwise averaged Strouhal number was quite negligible. With under suction, the spanwise dependence of various aerodynamic parameters existed, but was found to be not as significant as when no end suction was applied at all. With over suction, the flow situation was found to be practically no change from the optimal suction situation.

Cylinders with square cross-section: wake instabilities with incidence angle variation

The wakes behind square cylinders with variation in incidence angle are computed over a range of Reynolds numbers to elucidate the three-dimensional stability and dynamics up to a Reynolds number of Re = 300, based on the projected height of the inclined square cylinder. Three-dimensional instability modes are predicted and computed using a linear stability analysis technique and three-dimensional simulations, respectively. Depending on the incidence angle, the flow is found to transition to three-dimensional flow through either a mode A instability, or a subharmonic mode C instability. The mode A instability is predicted as the first-occurring instability at incidence angles smaller than 12° and greater than 26°, with the mode C instability predicted between these incidence angles. At a zero-degree angle of incidence, the wake instabilities closely match modes A, B and a quasi-periodic mode predicted in earlier studies behind square and circular cylinders. With increasing angle of incidence, the three-dimensional wake transition Reynolds number first increases from Re = 164 as the mode A instability weakens, before decreasing again beyond an incidence angle of 12° as the wake becomes increasingly unstable to the mode C instability, and then again to the mode A instability as the incidence angle approaches 45°. A spanwise autocorrelation analysis from computations over a cylinder span 20 times the square cross-section side length reveals that beyond the onset of three-dimensional instabilities, the vortex street breaks down with patterns consistent with spatio-temporal chaos. This effect was more pronounced at higher incidence angles.

Wake dynamics of external flow past a curved circular cylinder with the free stream aligned with the plane of curvature

Three-dimensional spectral/hp computations have been performed to study the fundamental mechanisms of vortex shedding in the wake of curved circular cylinders at Reynolds numbers of 100 and 500. The basic shape of the body is a circular cylinder whose centreline sweeps through a quarter section of a ring and the inflow direction lies on the plane of curvature of the quarter ring: the free stream is then parallel to the geometry considered and the part of the ring that is exposed to it will be referred to as the ‘leading edge’. Different configurations were investigated with respect to the leading-edge orientation. In the case of a convex-shaped geometry, the stagnation face is the outer surface of the ring: this case exhibited fully three-dimensional wake dynamics, with the vortex shedding in the upper part of the body driving the lower end at one dominant shedding frequency for the whole cylinder span. The vortex-shedding mechanism was therefore not governed by the variation of local normal Reynolds numbers dictated by the curved shape of the leading edge. A second set of simulations were conducted with the free stream directed towards the inside of the ring, in the so-called concave-shaped geometry. No vortex shedding was detected in this configuration: it is suggested that the strong axial flow due to the body's curvature and the subsequent production of streamwise vorticity plays a key role in suppressing the wake dynamics expected in the case of flow past a straight cylinder. The stabilizing mechanism stemming from the concave curved geometry was still found to govern the wake behaviour even when a vertical extension was added to the top of the concave ring, thereby displacing the numerical symmetry boundary condition at this point away from the top of the deformed cylinder. In this case, however, the axial flow from the deformed cylinder was drawn into the wake of vertical extension, weakening the shedding process expected from a straight cylinder at these Reynolds numbers. These considerations highlight the importance of investigating flow past curved cylinders using a full three-dimensional approach, which can properly take into account the role of axial velocity components without the limiting assumptions of a sectional analysis, as is commonly used in industrial practice. Finally, towing-tank flow visualizations were also conducted and found to be in qualitative agreement with the computational findings.

Studying Three-Dimensionality of Vortex Shedding Behind a Circular Cylinder with Mems Sensors

AbstractExperiments were made with 14 MEMS sensors situated along the span of a circular cylinder whose aspect ratio was 5. The signals of the MEMS sensors were sampled simultaneously as flow over the cylinder at Reynolds numbers of 104. The results of Wavelet analysis of the signals indicate that the percentage of time during which strong three-dimensionality of vortex shedding was detected is about 10%.As noted, strong three-dimensionality took place when the fluctuating amplitude of the signals was severely modulated and the vortex shedding frequency reduced appeared abnormally high or low. Further noted was that the addition of a splitter plate of 0.5 or one diameter in length behind the circular cylinder was not able to suppress the three-dimensionality of the flow.

Endwall heat transfer and fluid flow around an inclined short cylinder

Measurements of endwall heat transfer and flow field around a short single cylinder have been performed to examine the influence of cylinder inclination at low Reynolds number ( Re D = 1.0 × 10 4). Both ends of the cylinder are attached to the endwalls and the length-to-diameter ratio of the cylinder varies from 2.7 to 4, depending on the inclination angle. Endwall heat transfer contours (obtained from transient liquid crystals) and endwall flow visualization results consistently indicate that the interaction between the horseshoe vortices around the cylinder and the wakes shed from the cylinder varies with the inclination. Spanwise pressure gradient induced by the inclination causes: (i) skewing of the upstream main flow as it approaches the cylinder; (ii) formation of a jet-like flow immediately downstream of the cylinder, followed by its impingement onto the endwall; and (iii) skewed separation line along the cylinder span from the cylinder axis.