Time-averaged Velocity Fields Research Articles

Two-dimensional shear rate field and flow structures of a pseudoplastic fluid in a stirred tank using particle image velocimetry

For non-Newtonian fluids, an accurate determination of the shear rate is essential to optimize process parameters, which can lead to the improvement of the process efficiency. This work proposes the evaluation of an aqueous solution of carboxymethylcellulose (CMC) analyzing two azimuthal planes, AZ 0° and 45°, and four blade positions, AR 0°, 22.5°,45° and 67.5°, by ensemble-averaged and angle-resolved PIV measurements, respectively, in a stirred tank equipped with a pitched-turbine impeller. Results are shown in terms of time-averaged velocity, shear rate, apparent viscosity and Reynolds number fields. Differences between both PIV measurements approaches were significant in terms of velocity magnitude and characteristics of trailing vortices. The results demonstrate that the shear rate is strongly influenced by spatial resolution. The highest shear rates were obtained in the impeller region. The presence of a vortex above the blade resulted in high values of local Reynolds number, reflecting the presence of turbulence in that region.

Wind tunnel measurement of three-dimensional turbulent flow structures around a building group: Impact of high-rise buildings on pedestrian wind environment

The wind velocity and surface pressure of the model of a group of urban blocks made of low-rise buildings with a high-rise building in the center were measured using a wind tunnel. Not only the time-averaged velocity field, but also the turbulent statistics, i.e., the turbulent kinetic energy, normal component of the Reynolds stresses, gust factor (GF), and probability density function (PDF), and power spectrum density (PSD) of instantaneous velocity components were investigated. Based on the results, the impact of high-rise buildings on the general flow structure and the surrounding pedestrian wind environment was discussed. The presence of high-rise buildings drastically changes the pedestrian wind environment around buildings in terms of time-averaged and instantaneous flow properties due to the complex interaction between the flows around the building and in and above the surrounding street canyons. High-rise buildings create a large GF region where the downwash flow and the street flow collide. A clear correlation between the GF and the time-averaged horizontal velocity magnitude was observed regardless of the height of the central building. The PDF of instantaneous velocity components around the high-rise building was characterized by a large skew not only near the building corners of the high-rise building but also on the surrounding streets. The high-rise building produces large PSDs of the velocity fluctuation components, particularly near the upwind corner at a high frequency and on the surrounding street at an intermediate frequency. Furthermore, the results of the time-averaged and instantaneous flow properties provide a useful database for computational fluid dynamics (CFD) validation and model development studies.

DPM model segregation validation and scaling effect in a rotary drum

Discrete phase method (DPM) model was used to analyse rotary drum systems for segregation behavior. DPM simulations were performed for comparison with a dynamic segregation experimental measurement from the literature. This included dynamic segregation and time-averaged particle velocity field, which were validated with experimental data. In addition, a direct DPM and parcel scaled DPM simulation study was performed to analyse the effect of drum and particle parcel size scaling. The segregation dynamics was evaluated using the Lacey mixing index. This work shows segregation dynamics decreases with increasing drum size while keeping the same particle size. It further shows that for a given drum size the segregation dynamics deviate after a certain particle parcel scaling limit. The parcel scaling limit also increases with increasing drum size.

Influence of porous media coatings on flow characteristics and vortex-induced vibration of circular cylinders

The aerodynamic parameters and flow field characteristics of cylinders with and without a porous media coating (PMC) were experimentally investigated in a wind tunnel. This research explored the potential of using a PMC to control vortex-induced vibration (VIV). The PMCs were manufactured with four pores-per-inch values (PPI = 15, 20, 30, and 40) and three depths, (d/D=0.125, 0.25, and 0.5, where d is the depth of the coating and D is the diameter of the bare cylinder). The instantaneous drag and lift forces were measured in static tests. The results showed that all the PMCs could decrease the fluctuation of the forces. The root-mean-square lift force was reduced by up to 98% with a coating of PPI = 15 and d/D=0.5 at Re = 5.2×104. The flow fields were visualized using a particle image velocimetry (PIV) system and analyzed with time-averaged velocity fields, wake velocity profiles, and turbulence kinetic energy distributions. For PMCs with smaller PPI values and greater depths, the wake vortex formed further away from the cylinder. Then the dynamical responses were tested for elastically supported models. Not all the PMCs could suppress the VIV. When PPI < 30, the PMC decreased the VIV amplitude. For each PPI, a greater depth resulted in a lower amplitude. The VIV amplitude for a coated cylinder was reduced to 4% of that for the bare cylinder. When PPI > 30, the PMC enhanced the VIV, with a greater depth resulting in a higher amplitude. When PPI = 30, the PMC could either increase or decrease the VIV amplitude, depending on the depth. The flow fields around the oscillating cylinder were also analyzed to reveal the effect of the PMC on the wake vortex shedding behavior.

Proper orthogonal decomposition analysis of coherent motions in a turbulent annular jet

A three-dimensional incompressible annular jet is simulated by the large eddy simulation (LES) method at a Reynolds number Re = 8 500. The time-averaged velocity field shows an asymmetric wake behind the central bluff-body although the flow geometry is symmetric. The proper orthogonal decomposition (POD) analysis of the velocity fluctuation vectors is conducted to study the flow dynamics of the wake flow. The distribution of turbulent kinetic energy across the three-dimensional POD modes shows that the first four eigenmodes each capture more than 1% of the turbulent kinetic energy, and hence their impact on the wake dynamics is studied. The results demonstrate that the asymmetric mean flow in the near-field of the annular jet is related to the first two POD modes which correspond to a radial shift of the stagnation point. The modes 3 and 4 involve the stretching or squeezing effects of the recirculation region in the radial direction. In addition, the spatial structure of these four POD eigenmodes also shows the counter-rotating vortices in the streamwise direction downstream of the flow reversal region.

On the challenges of precise velocity measurements in vertical convective wall jets

For the transition of our energy supply towards a higher share of renewables, thermal energy storage (TES) systems are, besides electric batteries and chemical energy storage systems, one promising solution to overcome the volatile nature of renewable energy sources. For the most efficient operation, the liquid storage material in the tank should be stratified by its temperature-dependent density. As a result, the cold fluid remains at the bottom, and the heated fluid rises to the top (Alva et al. (2018)). Typically steel tanks are used for TES, and thus, the wall material has a thermal diffusivity that is one to two orders of magnitudehigher than that of the storage fluid. Consequently, the tank’s sidewalls work as a thermal bridge between the stratified layers. In recent studies, the authors have shown that the resulting heat flux induces two counterdirected, convective wall jets near the sidewalls of the tank, which increase mixing of the stratification and thus lowers the exergy content and the storage efficiency (Otto et al. (2019, 2020)). Using a model experiment of a TES, the entire vertical extent of the detected wall jets is investigated. Hence, the typical flow structures of vertical, natural convection under the influence of non-zero temperature gradients in the ambient fluid can be analyzed, which can help to improve storage tanks in the future. The velocity in the region of the wall jets is measured via 2d particle-image velocimetry (PIV) in a rectangular model experiment of 750mm height on a base area of 375mm×375mm made from polycarbonate. The jets evolve on the surface of an aluminum plate simulating the storage tank’s sidewall. The measuring system consists of four cameras with a resolution of 2160×2560 pixels combined with objective lenses with 100mm focal length capturing the raw images in a plane perpendicular to the aluminum wall. A Nd:YAG laser with a wavelength of 532nm illuminates the measuring plane. Simultaneously using up to four cameras adjacent to each other and stitching their resulting vector fields, the vertical extent of the field of view increases from 38mm up to 140mm. Despite this, the field of view is still much smaller than the vertical extent of the model experiment, so that seven consecutive runs are performed to cover the entire height. Disturbing reflections of the laser light sheet on the aluminum wall are eliminated using optical filters for the cameras that are opaque for the green laser light in combination with fluorescently (Rhodamine B) dyed PMMA tracer particles with a diameter between 1–20μm. The particles emit light at a wavelength of 610nm (orange light) and can therefore be detected through the cameras’ filters. During four separate measuring periods, where each lasts for two minutes, double frame images are captured with a time difference of 19.981 ms (maximum possible value) at a measuring frequency of 7 Hz. Figure 1 shows a schematic of the camera setup next to the model experiment and the measurement and evaluation procedure to finally receive one time-averaged velocity field per measuring period of the full height of the experiment. The raw data evaluation process starts with calculating the vector fields of all cameras used at a certain measuring position and stitching them to one flow field of this position. Since the wall jets’ horizontal extents are with 2–7mm relatively small and they show high velocity gradients, the raw images are evaluated in both single-frame and double-frame mode. With a velocity threshold that corresponds to a pixel displacement of 1/4 of the interrogation window size and the time difference of the single-frames, the resulting vector fields are masked and merged into one final vector field. This vector field consists of high velocities evaluated in double-frame mode and low velocities evaluated in single-frame mode (see Figure 2) thus minimizing the relative error. The algorithm used in this work is similar to the multi-frame PIV approach introduced by Hain and K¨ahler (2007). Figure 3 shows the time-averaged results of the first measuring period for each of the seven measuring positions in height.

Experimentally obtained velocity and pressure fields of an open channel flow around a cylinder using RIM-SPIV

The quantification of velocity and pressure fields over streambeds is important for predicting sediment mobility and water exchange between stream and sediment interstitial spaces (Schmeeckle and Nelson, 2003; Tonina and Buffington, 2009). The latter is typically referred as hyporheic flow, which consists of surface water that flows through the streambed sediment pores (Tonina and Buffington, 2009). These fluxes are mainly driven by pressure gradients at the water sediment interface. In this paper, we report an experimental investigation of the time-averaged velocity and pressure field, quantified in a set of laboratory experiments using stereo PIV (Particle Image Velocimetry) with a non-toxic index-matched fluid, for an open channel flow around a barely submerged vertical cylinder as a model for plant stalk over a plane bed of coarse granular sediment, mimicking a stream gravel bed. This is the first time that such a velocity and pressure field is characterized experimentally for a free surface flow with irregular floor contour.

An in-depth numerical analysis of transient flow field in a Francis turbine during shutdown

Power production from intermittent renewable energy resources, such as solar and wind, has increased in the past few decades, leading researchers and engineers to establish techniques to preserve a stable electrical grid. Consequently, hydraulic turbines are being used more frequently in transient operating modes to regulate the grid. The present work provides a comprehensive numerical study on the transient flow field of a high-head Francis turbine model throughout the shutdown sequence. The computations were performed using OpenFOAM, utilizing the SST-SAS turbulence model. A Laplacian smoothing scheme is employed to conduct the mesh deformation of the guide vane domain. The time-averaged draft tube velocity field at the steady Best Efficiency Point (BEP) is validated against experimental data. Then different aspects of the transient flow field in the shutdown sequence are carefully assessed and explained for the first time. Short-Time Fourier Transform (STFT) analysis is carried out on the fluctuating part of the static pressure and force signals. High-amplitude low-frequency oscillations, due to the formation of a Rotating Vortex Rope (RVR) were observed during a specific period of the shutdown sequence. Thereafter, at deep part load conditions, the RVR vanishes and, a wide range of stochastic frequencies are identified at minimum load. A signal coherence analysis was accomplished to distinguish the deterministic and stochastic frequencies. The variation of the velocity field in the draft tube is described in detail with the help of velocity triangles. An in-depth explanation of the formation and variation of vortical structures during the whole sequence is presented. The physical mechanism of formation and destruction of the RVR is thoroughly explained.

Turbulence in a wedge: The case of the mixing layer

The ultimate goal of a sound theory of turbulence in fluids is to close in a rational way the Reynolds equations, namely to express the tensor of turbulent stress as a function of the time average of the velocity field. Based on the idea that dissipation in fully developed turbulence is by singular events resulting from an evolution described by the Euler equations, it has been recently observed that the closure problem is strongly restricted, and that it implies that the turbulent stress is a non local function in space of the average velocity field, a kind of extension of classical Boussinesq theory of turbulent viscosity. This leads to rather complex nonlinear integral equation(s) for the time averaged velocity field. This one satisfies some symmetries of the Euler equations. Such symmetries were used by Prandtl and Landau to make various predictions about the shape of the turbulent domain in simple geometries. We explore specifically the case of mixing layer for which the average velocity field only depends on the angle in the wedge behind the splitter plate. This solution yields a pressure difference between the two sides of the splitter which contributes to the lift felt by the plate. Moreover, because of the structure of the equations for the turbulent stress, one can satisfy the Cauchy-Schwarz inequalities, also called the realizability conditions, for this turbulent stress. Such realizability conditions cannot be satisfied with a simple turbulent viscosity.

High Resolution 2.5D PIV Measurements of the Flow Fields Generated by Small Fans

Abstract The free jets of an axial and a centrifugal fan have been scanned by a specialized particle image velocimetry (PIV) set-up, which allows for volumetric scans of the time-averaged velocity field. Both of these fans have similar dimensions of approximately 70 mm x 70 mm x 25 mm. A classic PIV set-up was combined with a precise linear stage to move the fans through the laser fan beam in small steps, creating a dense array of measurement planes. Two components of the time-averaged velocity field are captured by the first 2.5D scan. Another scan, with the fan rotated by 90° about its outlet surface normal, captures the missing third velocity component. This article describes the details of the measurement set-up, and mentions measures concerning seeding, reflections, and calibration. In the signal processing stage, two independent sets of gathered image data have to be processed, producing two sets of velocity image frames. These are subsequently combined using gridded interpolation in order to obtain a 3D velocity field. Specifically devised software tools allow for a CFD-like analysis and visualization of the flow field. Typical parameters of the generated jets, like the spreading and rotation rates, are calculated from the measurement data and details of the outlet flow fields are investigated. The interpolated data are also used to analyze the influence of an assumed coarser measurement grid resolution on the results for the obtained outlet flow fields.

Turbulent convection in a cube with mixed thermal boundary conditions: low Rayleigh number regime

Turbulent thermal convection was numerically investigated in a cubic cavity under homogeneous and inhomogeneous heating for Rayleigh number Ra=107 and Prandtl number Pr=6.46. Inhomogeneous heating was created only at the lower boundary using mixed boundary conditions. Three configurations of the heated regions distribution of the same heating area were considered. The total heat flux through the lower boundary substantially depends on the distribution of the heated regions and increases with decreasing of the heaters size, which is in a good agreement with Ripesi et al., 2014 and Bakhuis et al., 2018. It was found that in turbulent thermal convection under inhomogeneous boundary conditions large-scale circulation (LSC) is formed. Dynamics and structure of LSC strongly depends on the distribution of conducting regions. In case of Rayleigh-Bénard convection, the main flow is more complex with higher-order modes prevailing. Time-averaged velocity field revealed the existence of two vortex rings rotating in opposite directions and located near horizontal walls. Decomposing the velocity into free-slip modes allowed us to find that these vortex rings are stable and provide the most of system energy. The absence of mean LSC results in a specific convective heat transfer mechanism when mean and turbulent heat fluxes are spatially separated.

LES study on the working mechanism of large-scale precessing vortices and energy separation process of Ranque-Hilsch vortex tube

In this paper, a large eddy simulation model (LES) was adopted to analyse the large-scale precessing vortices and energy separation in a Ranque–Hilsch vortex tube. By comparing the time-averaged axial velocity field between the Laser Doppler velocimetry data and the numerical results, the feasibility of the LES model was confirmed. The 2D instant flow field presents two vortex structures of secondary circulation flow at the cold end, and precessing vortices inside the tube. It also reveals two opposite flows in the axial and radial directions, and the precessing vortices formed by the reverse flow turn towards the main flow. Then, the 3D coherent structure inside the vortex tube was obtained by the vortex identification method for the first time. The basic vortex structure inside the vortex tube consists of the vortex body, detached vortex, and fragmentised detached vortex. Through the evolution of the 3D vortex structure, it was found that the detached vortices experienced a life cycle of growth, shedding, fragmenting, and vanishing. Benefitting from the vortex shedding processes, the precessing vortices overcame the adverse radial pressure gradient and drove part of the reverse flow towards the main flow from the low-pressure zone to the high-pressure zone. Through these processes, the vortex core precession that drives the reciprocating motion of the gas parcels near the reverse flow boundary was established, and energy could be transferred from the inner layer to the outer layer through a heat pump cycle.

Influence of Aeration Microporous Aperture on Oxygen Mass Transfer Efficiency in Terms of Bubble Motion Flow Field

Microporous aeration has been widely used to restore eutrophic water bodies. The gas–liquid mass transfer in the aeration process has a significant influence on the improvement of water quality. Therefore, the influence mechanism of oxygen mass transfer is worth studying. However, the influence of bubble movement characteristics on oxygen mass transfer has not been systematically studied. Thus, the present study explored the influence mechanism of microporous apertures on oxygen mass transfer in terms of bubble motion characteristics by investigating the oxygen mass transfer process and the feature of bubble movement under different aeration microporous aperture sizes. The results showed that the mass transfer efficiency was reduced as the micropore aperture increased from 200 to 400 μm. and the reduction rate was 7.17% when the aperture increased from 200 to 300 μm, which was lower than that from 300 to 400 μm (19.17%). Furthermore, the micropore aperture showed a positive correlation with the time-averaged velocity field. With the increase in aperture, the bubble velocity gradient (from the center to both sides of the edge) increased from about 0.2 to 0.4 m/s, which increased the oxygen mass transfer effect. The increase of micropore aperture caused the increase of average Sauter bubble diameter and the decrease of specific surface area of bubbles. In addition, the negative effects of the reduction of specific surface area and the shortening of bubble residence time on oxygen mass transfer efficiency were greater than the positive effects of the increase of turbulent kinetic energy. When the aperture changes from 300 to 400 μm, the shortening of bubble residence time should have played a major role. This study provides some theoretical parameters for investigating the mechanism of oxygen mass transfer in microporous aeration.

ЧИСЛЕННОЕ ИССЛЕДОВАНИЕ ЗАКРУЧЕННОГО ТУРБУЛЕНТНОГО ТЕЧЕНИЯ В КАНАЛЕ С ВНЕЗАПНЫМ РАСШИРЕНИЕМ

A strongly swirling turbulent flow through an abrupt expansion is studied using the highly resolved DNS, LES, and SAS to shed more light on a stagnation region and spiral vortex destruction, though these methods require high computational expenses. The vortex fracture induced by a sudden expansion resembles the so-called vortex rope that occurs in hydropower draft tubes. It is known that large-scale spiral vortex structures can be captured by regular RANS turbulence models. In this paper, a numerical study of a strongly swirling flow, which abruptly expands, is carried out using the Reynolds stress models SSG / LRR-RSM and EARSM with experimental measurements implemented by Dellenback et al. (1988). Calculations are carried out using the finite volume method. The flow dynamics is studied at the Reynolds number of 3.0 × 104 at almost constant large swirl numbers of 0.6. The time-averaged velocity and pressure fields, as well as the root-mean-square values of the velocity fluctuations are recorded and studied qualitatively. The obtained results are compared with known experimental data. The aim of this work is to test the ability of the models to describe anisotropic turbulence. It is shown that the SSG / LRRRSM model is more appropriate for studying such flows.

Computational and experimental study of 3D flow near the cube immersed in the turbulent free convection boundary layer on a vertical heated plate

Results of a coordinated computational and experimental study of time-averaged velocity and temperature fields in the vicinity of an adiabatic cube that is inserted into the turbulent free convection vertical-plate boundary layer are presented. The numerical simulation was based on the steady-state RANS approach using the k-ω SST turbulence model and a version of the differential Reynolds stress model (DRSM). The hot-wire technique was used for velocity measurements, simultaneously with temperature measurements by an accompanied “cold” wire. Two turbulence models produced similar vortex flow structures near the obstacle; however some important quantitative distinctions were observed. The velocity value profiles predicted for the middle vertical plane showed generally a good accordance with the hot-wire measurements carried out in this plane, especially in the DRSM case.

Large-eddy simulation of turbulent flows over an urban building array with the ABLE-LBM and comparison with 3D MRI observed data sets

In this article we describe the details of an ABLE-LBM (Atmospheric Boundary Layer Environment-Lattice Boltzmann Model) validation study for urban building array turbulent flow simulations. The ABLE-LBM large-eddy simulation results were compared with a set of 3D magnetic resonance image (MRI) velocimetry data. The ABLE-LBM simulations used the same building layout and Reynolds numbers operated in the laboratory water channel. The building set-up was an evenly spaced orthogonal array of cubic buildings (height = H) with a central tall building (height = 3H) in the second row. Two building orientations, angled with 0°and 45° wind directions, were simulated with ABLE-LBM. The model produced horizontal and vertical fields of time-averaged velocity fields and compared well with the experimental results. The model also produced urban canyon flows and vortices at front and lee sides and over building tops that were similar in strength and location to the laboratory studies. The turbulent kinetic energy associated with these two wind directions were also presented in this simulation study. It is shown that the building array arrangement, especially the tall building, has a great effect on turbulent wind fields. There is a Karman vortex street on the lee side of the tall building. High turbulent intensity areas are associated with the vortex shedding motions at building edges. In addition, the wind direction is a very important factor for turbulent wind and kinetic energy distribution. This validation study indicated that ABLE-LBM is a viable simulation model for turbulent atmospheric boundary layer flows in the urban building array. The computational speed of ABLE-LBM using the GPU has shown that real-time LES simulation is realizable for a computational domain with several millions grid points.

Measuring the velocity field of a shear-coaxial, cryogenic flame in a high-pressure rocket thrust chamber

High-speed imaging was used to visualize one of the transcritical flames in a multi-injector, sub-scale rocket thrust chamber at pressures up to 80 bar. Image correlation velocimetry (ICV) was applied to the imaging to obtain quantitative information on the flow field from the shear-coaxial injectors. ICV was used to track surface irregularities on the liquid oxygen (LOX) jet in imaging filtered to blue wavelengths. By choosing the interrogation area carefully, only the LOX jet was effectively tracked, excluding the coaxial H2 flow, and the time-averaged velocity field was reconstructed. Due to the transient nature of the tracked features, which frequently change shape or disappear, the averaged ICV result underestimates the absolute values of velocity. Therefore, the averaged values were scaled by the mean of the instantaneous velocity maxima. A second, reference measurement of LOX jet propagation speed was calculated using dynamic mode decomposition (DMD). The results were consistent following the aforementioned correction of the ICV values. Comparing the ICV fields for two different operating conditions showed a marked difference in the axial velocity distribution and lateral expansion of the LOX jet, demonstrating the potential of the method in studying injection in rocket combustion chambers.

Influences of free surface jump conditions and different [formula omitted] SST turbulence models on breaking wave modelling

A two-phase flow Computational Fluid Dynamics (CFD) model is employed for both spilling and plunging breaking wave simulations. A numerical wave tank is built to evaluate the performance of two different free surface modelling approaches (i.e., continuous free surface conditions and free surface jump conditions) and three k−ω SST turbulence models (i.e., the original k−ω SST, the buoyancy modified k−ω SST and the free surface k−ω SST (a newly proposed model)). The influences of the free surface modelling approaches and the turbulence models are investigated by comparing with the published experimental measurements in terms of breaking point, free surface elevations, time-averaged velocity field, time-averaged turbulent kinetic energy and general turbulent behaviour, respectively. Overall, the free surface k−ω SST with the free surface jump conditions performs best in terms of the accuracy of the predictions against the experimental data and the capture of the physical breaking phenomena, for instance, the trapped air pocket and the development of the free surface in the surf zone.

Study on Flow Characteristic of Sub-/Super-Sonic Mixing Layer

In order to obtain the flow characteristics of sub-super-sonic mixing layer including velocity distribution, pressure distribution and development of mixing layer, experimental and numerical investigations were conducted. PIV technique was employed to measure the two-dimensional velocity distribution in the experiment while the standard k-ω turbulent considering the effect of compressibility was adopted to simulate the flow characteristic of mixing layer. The Mach number of subsonic stream and supersonic one was 0.11 and 1.32, respectively. The results show the flow of mixing layer is temporally transient. The interface between two streams lies initially as an approximately line segment; afterward, it becomes wrinkled and distorted; finally, it breaks up. The mixing layer develops linearly along streamwise direction in the time averaged velocity field with a growth rate of 0.135. The velocity and total pressure distributions in the mixing layer are self-similar.

Evaluation of a Near-Wall-Modeled Large Eddy Lattice Boltzmann Method for the Analysis of Complex Flows Relevant to IC Engines

In this paper, we compare the capabilities of two open source near-wall-modeled large eddy simulation (NWM-LES) approaches regarding prediction accuracy, computational costs and ease of use to predict complex turbulent flows relevant to internal combustion (IC) engines. The applied open source tools are the commonly used OpenFOAM, based on the finite volume method (FVM), and OpenLB, an implementation of the lattice Boltzmann method (LBM). The near-wall region is modeled by the Musker equation coupled to a van Driest damped Smagorinsky-Lilly sub-grid scale model to decrease the required mesh resolution. The results of both frameworks are compared to a stationary engine flow bench experiment by means of particle image velocimetry (PIV). The validation covers a detailed error analysis using time-averaged and root mean square (RMS) velocity fields. Grid studies are performed to examine the performance of the two solvers. In addition, the differences in the processes of grid generation are highlighted. The performance results show that the OpenLB approach is on average 32 times faster than the OpenFOAM implementation for the tested configurations. This indicates the potential of LBM for the simulation of IC engine-relevant complex turbulent flows using NWM-LES with computationally economic costs.