Entire Flow Field Research Articles

A numerical study on the effects of using combined flow fields and obstacles on the performance of proton exchange membrane fuel cells

AbstractThe flow field structure has an important influence on the comprehensive performance of the proton exchange membrane fuel cell (PEMFC). This research investigates the effects of combined flow fields on the distribution of species concentration, the pressure drop, and the overall performance of PEMFC based on the polarization curve and power consumption ratio (PCR). Obstacles are arranged in different areas to study the mass transfer of the gas inside the combined flow field. The results show that the combined serpentine flow field improves the concentration distribution of species and the performance of the cell is enhanced with the increase of the proportion of the single‐channel serpentine structure in the combined flow field, but the PCR is decreased. The energy efficiency conversion in the low voltage region is better when the obstacles are arranged in the entire flow field. Moreover, the vortex effect generated by the obstacles enhances the convection ability under the rib parallel to the inlet direction, while the transverse vortex and secondary flow perpendicular to the inlet direction are weakened by the flow field structure so that the mass transfer of gas is enhanced.

Poster Session 1

Although the shock wave propagation in the dusty gas medium is widely used in research, astrophysics, military, and industrial applications, the shock wave in a self-gravitating mixture of van der Waals gas and a pseudo-fluid of inert solid particles in a rotating medium, is not well understood. In the present paper, the strong exponential shock wave propagation in a self-gravitating mixture of non-ideal gas and a pseudo-fluid of small solid particles is modelled for unsteady adiabatic and isothermal flows in a rotating medium. In our model, the solid particles are considered as chemically inert pseudo-fluid, and the equilibrium flow conditions hold in the entire flow field region. The similarity solutions are derived for isothermal and adiabatic flows. The vorticity vector components, and isothermal and adiabatic compressibility's are also taken into account. It is shown that the zero-temperature gradient supposition brings the reflective changes in pressure, axial vorticity vector, density, and compressibility distributions in contrast to the adiabatic flow. The shock strength decreases, and the compressibility increases due to the zero-temperature gradient consideration. Also, the effects of the problem parameters on shock waves and the distributions of the flow variables velocity, density, etc., are discussed in detail. It is remarkable to note that due to the consideration of a self-gravitating mixture or with an increase in the ratio of the density of solid particles to the initial density of the gas, the shock strength increases; whereas due to the consideration of non-idealness of the gas or rotating medium the shock strength decreases.

Simulation and Validation of Cavitating Flow in a Torque Converter with Scale-Resolving Methods

The purpose of this paper is to study the mechanism and improve the prediction accuracy of transient torque converter cavitation flow by the application of scale-resolving simulation (SRS) methods with particular focus on cavitation vortex flow. Firstly, the numerical analysis of the entire internal flow field of the torque converter was carried out using different turbulence models, and the prediction accuracy of the hydraulic characteristics of the adopted models was analyzed and validated via test data. Secondly, the cavitation and turbulence behavior in the internal flow field were analyzed, and the blade surface pressure according to different turbulence models was compared and validated through test data. Finally, the transient cavitation characteristics of the flow field were studied based on the stress-blended eddy simulation (SBES) model. The prediction accuracy of the cavitation flow field simulation of the torque converter is significantly improved using the SRS model. The maximum error of capacity constant, torque ratio and efficiency are reduced to 3.1%, 2.3%, and 1.3% at stall, respectively. The stator is more prone to cavitation than pump and turbine. The SBES model has the highest prediction accuracy in multiple measurement points, and the maximum deviation can reach 13.32% under stall. Attached cavitation bubbles and periodic shedding cavitation can be found in the stator, and the evolution period is about 0.0036 s, i.e., 279 Hz. The prediction accuracy of different models was compared and analyzed, which has important guiding significance for the high-precision prediction and analysis of fluid machinery.

Impacts of seasonal flow variation on riverine hydrokinetic energy resources and optimal turbine location – Case study on the Rivière Rouge, Québec, Canada

Hydrokinetic energy resource assessment is a crucial prerequisite for strategic turbine deployment and energy extraction. Despite advancements in analytical tools, resource assessment is often completed without detailed investigation of spatial and temporal flow variation and implications on optimal turbine placement. A case study was conducted on the Rivière Rouge, Québec, Canada to estimate the hydrokinetic energy resource, to locate the optimal turbine placement, and to study the impact of seasonal flow variation. The primary optimal turbine location did not change, but the second, third, and fourth optimal locations were impacted. Assuming a hypothetical deployment of one turbine with a 1 m2 swept area, the theoretical hydrokinetic energy resource for the site was 21.8 MWh per year in the optimal turbine locations and 6.2 MWh per year using the reach-averaged velocity. This difference illustrates the need to consider the entire velocity flow field in hydrokinetic energy assessments. To conduct the assessment, field data were collected with an acoustic Doppler current profiler and a global positioning system for hydrodynamic model generation, calibration, and validation using the software TELEMAC-2D. The mean absolute percentage errors of the model in the areas of interest were 14.8% for calibration and 22.9% and 19.4% for validation.

A CFD-based porous medium model for simulating municipal solid waste incineration grates: A sensitivity analysis

This study starts from a generalized CFD-based porous medium model developed in previous work simulating the combustion of municipal solid waste (MSW) on incineration grates. In this paper, three specific bed models are compared: a newly developed whole moving bed model, a newly developed multi-zone model, and a fixed bed model. Although the whole moving bed model covers the entire gas flow field, this advantage is offset by a high computational cost. In the multi-zone model, different zones of the waste bed are computed consecutively. This helps to reduce the computational time by about 75% but causes a loss of accuracy in predicting the gas flow field at the transition between the zones. For the fixed bed model, the walking column approach is needed. Additional accuracy loss is introduced but the computational time is significantly reduced even further compared to the multi-zone model. Because of the trade-off between computational cost and accuracy and the great uncertainty of the model parameters in industrial practice, the fixed bed model is suggested for simulating industrial grate-firing systems. In addition to these moving bed modeling strategies, this study also investigates how sensitive model results are to the assumed minimum and maximum solid fractions, which determine the evolution of porosity along the grate. The results show that the conversion rates are relatively insensitive to these criteria within the investigated range. Conversely, the effective surface area greatly influences the combustion characteristics as it affects the drying and char conversion rate and governs the temperature difference between the solid and gas phases. This finding calls for a better understanding of the evolution of the effective surface area and equivalent particle diameter during the combustion of MSW.

Experimental study on the combustion process of a kerosene-fueled scramjet with strut injection

The ground combustion test was used to study the effects of kerosene fuel on the start-up ignition and flame stabilization of a scramjet with reverse strut injection. The test analyzed the changes of flow field wave system and flame propagation law under various working conditions after pilot hydrogen was injected into the combustor. The results showed that when hydrogen was injected into the combustor, it started to combust in only 0.0128 s. The heat released by combustion led to the generation of reverse pressure gradient, which made the wave system move forward and concentrate near the backward step. In the case of hydrogen self-ignition, the entire flow field remained stable combustion. At t = 0.07 s, kerosene was gradually injected into scramjet and ignited by pilot flame. The pressure at the monitoring point increased rapidly from 0.064 MPa to 0.135 MPa, and severe combustion occurred in the cavity. The flame began to propagate from the shear layer to the low-speed recirculation zone. Subsequently, the pressure of the monitoring point was reduced to 0.121 MPa, and the combustion flame continuously passed from the cavity downstream. When the hydrogen was removed, the pressure was reduced to 0.09 MPa, and the flame in the cavity was relatively weakened. However, the rapid ignition condition of kerosene could still be achieved, and the combustion flame continued to generate. After fuel began to be gradually removed, kerosene could not maintain continuous flame combustion due to the reduction of injection volume. The combustor changed between ignition and flameout, showing periodic oscillation with a period of 4.8 ms.

Fast prediction of indoor airflow distribution inspired by synthetic image generation artificial intelligence.

Prediction of indoor airflow distribution often relies on high-fidelity, computationally intensive computational fluid dynamics (CFD) simulations. Artificial intelligence (AI) models trained by CFD data can be used for fast and accurate prediction of indoor airflow, but current methods have limitations, such as only predicting limited outputs rather than the entire flow field. Furthermore, conventional AI models are not always designed to predict different outputs based on a continuous input range, and instead make predictions for one or a few discrete inputs. This work addresses these gaps using a conditional generative adversarial network (CGAN) model approach, which is inspired by current state-of-the-art AI for synthetic image generation. We create a new Boundary Condition CGAN (BC-CGAN) model by extending the original CGAN model to generate 2D airflow distribution images based on a continuous input parameter, such as a boundary condition. Additionally, we design a novel feature-driven algorithm to strategically generate training data, with the goal of minimizing the amount of computationally expensive data while ensuring training quality of the AI model. The BC-CGAN model is evaluated for two benchmark airflow cases: an isothermal lid-driven cavity flow and a non-isothermal mixed convection flow with a heated box. We also investigate the performance of the BC-CGAN models when training is stopped based on different levels of validation error criteria. The results show that the trained BC-CGAN model can predict the 2D distribution of velocity and temperature with less than 5% relative error and up to about 75,000 times faster when compared to reference CFD simulations. The proposed feature-driven algorithm shows potential for reducing the amount of data and epochs required to train the AI models while maintaining prediction accuracy, particularly when the flow changes non-linearly with respect to an input.

Effect of relative humidity on the desulfurization performance of calcium-based desulfurizer

Low desulfurization efficiency impedes the wide application of dry desulfurization technology, which is a low-cost and simple process, and one significant solution is the development and manufacture of high-performance desulfurizers. In this study, firstly, a steam jet mill was used to digest quicklime; then, we utilized numerical simulation to study the flow field distribution and analyze the driving factors of quicklime digestion; and lastly, the desulfurization performance of the desulfurizer was evaluated under different relative humidities. The results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional desulfurizers. Also, the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state, with high crushing intensity and good particle acceleration performance. Sufficient contact with the nascent surface maximizes the formation of slaked lime. The experiments demonstrated that the operating time with 100% desulfurization efficiency and the “break-through” time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers, and has significant advantages, especially at low flue gas relative humidity. Compared with traditional desulfurizers, the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature, and the failure temperature is 1.625 times that of traditional desulfurizers. This work breaks through the technical bottleneck of low dry desulfurization efficiency, which is an important step in pushing forward the application of dry desulfurization.

Numerical Investigations of Laminar Separation Bubbles Under the Influence of Periodic Gusts

Direct numerical simulations were performed to investigate the behavior of laminar separation bubbles subject to vertical gusts in an airfoil flow. Oscillating boundary-layer flows containing gusts—including unsteady pressure gradients—were prescribed via boundary conditions as well as forcing terms on a domain located in the upper rear section of a natural laminar flow airfoil. For this hybrid approach, unsteady Reynolds-averaged Navier-Stokes (URANS) simulations of the entire flowfield were carried out in conjunction with the so-called disturbance velocity approach, providing transient boundary conditions for the direct numerical simulation. A steady-state reference case with a Reynolds number of is compared and validated with results from wind tunnel experiments. Results of simulations at four different gust frequencies at the same amplitude , each with and without additional disturbances to the boundary layer introducing oblique resonance, are presented and discussed in this paper. The time-dependent behavior of convective instability modes is evaluated by using the continuous wavelet transform and linear stability theory with an unsteady extension. Furthermore, the contribution of the absolute instability—which appears to be larger in the case of oscillating flow compared to the steady-state case—is discussed. Lock-in effects are identified at high gust frequencies.

Investigation of pressure pulsation induced by quasi-steady cavitation in a centrifugal pump

To study the pressure pulsations induced by quasi-steady cavitation in a centrifugal pump, the pressure pulsations at the pump inlet and outlet were experimentally investigated with the development of cavitation. Moreover, the internal flow characteristics in the pump during the process were numerically determined. The numerical simulation results agreed well with the results obtained from the experimental test, verifying the accuracy of the numerical simulation. Furthermore, the cavitation-induced pump inlet and outlet pressure pulsations of the centrifugal pump were analyzed by wavelet analysis and fast Fourier transform, and the cavitation incipient point and occurrence of the unstable cavitation point were obtained. The results of both wavelet analysis and fast Fourier transform show that in the quasi-steady cavitation stage of the centrifugal pump at the design flow rate, the pump inlet and outlet pressure pulsations are significantly increased at twice the axial frequency, while the other axial frequency components are weak and the internal flow is stable. With the development of cavitation in the pump, the pump inlet and outlet pressure pulsations at the axial frequency and its multiples afford some obvious broadband pulsations. To investigate the mechanism of quasi-steady cavitation-induced pressure pulsation in the centrifugal pump, the dynamic mode decomposition was used for internal flow field analysis. The results show that different inflow states lead to obvious differences in the internal flow and unsteady flow structures. There are complex pressure pulsation characteristics dominated by different frequencies in the centrifugal pump. Blade passing frequency plays an important role in the entire flow field, and its mechanism has been analyzed. This research will provide experimental and theoretical support for quasi-steady cavitation recognition and help researchers improve the operation stability of the centrifugal pump.

The effects of thermal radiation on unsteady MHD free convective flow through the porous medium between two vertical plates with Hall effects

AbstractThe effects of thermal radiation and Hall current on magnetohydrodynamic free convection three‐dimensional flow in a vertical channel filled with a porous medium have been studied. We consider an incompressible viscous and electrically conducting incompressible viscous fluid in a parallel plate channel bounded by a loosely packed porous medium. The fluid is driven by a uniform pressure gradient parallel to the channel plates, and the entire flow field is subjected to a uniform inclined magnetic field of strength inclined at an angle of inclination with the normal to the boundaries in the transverse xy‐plane. The temperature of one of the plates varies periodically, and the temperature difference between the plates is high enough to induce radiative heat transfer. The effects of various parameters on the velocity profiles, the skin friction, the temperature field, and the rate of heat transfer in terms of their amplitude and phase angles are shown graphically.

FLOW VISUALIZATION AND FLOW PATTERNS IN A FLAT-PLATE POLYPROPYLENE PULSATING HEAT PIPE

The two-phase flow structure in a flat polymeric pulsating heat pipe (PHP) is studied experimentally by high-speed imaging and digital image processing. While flow patterns in tubular pulsating heat pipes can be studied by inserting a short transparent section in a certain position along the channel, in flat PHPs built using transparent plastic sheets one can visualize the entire flow field in the adiabatic region between the evaporator and the condenser. High-speed movies were enhanced by digital image processing to highlight the liquid-vapor interfaces. Different flow patterns were identified, and sorted into a simple flow pattern map.

Unsteady Aerodynamics of High Lift Systems using Overset Mesh

High lift devices facilitate the achievement of higher Cl on take-off and landing. But the motion of the high lift devices causes unsteady effects that have a significant influence on the resulting lift and drag forces. Hence a 2D unsteady numerical simulation during the retraction of a slat of HL-CRM is conducted to understand the unsteady effects produced during slat motion. Overset grid technique was employed to facilitate flexible motion of the slat. The simulation was carried out using OpenFOAM. It is observed that the value of lift coefficient decreases and drag coefficient increases in steady-state cases, because of the wake region created behind the slat at deployed position and airfoil. As in the transient case, there are huge fluctuations at the beginning of the motion and the fluctuations stabilize at the end emphasizing that the position of the slat during motion affects the entire flow field.

Hydrodynamics characteristics of non-uniform inflow in reactor coolant pump based on time-resolved tomographic particle image velocimetry

Non-uniform inflow at the inlet of a reactor coolant pump generates performance variations, such as in the head, efficiency, cavitation, and vibrations. The three-dimensional velocity and pressure for non-uniform inflow are reconstructed via time-resolved tomographic particle image velocimetry to evaluate its effect on the reactor coolant pump. Five volume velocity fields were reconstructed through the multiplicative algebraic reconstruction technique, which constitutes the entire non-uniform flow field. The statistics of the velocity fields were used to study the non-uniform inflow characteristics. The non-uniform inflow contains two large-scale vortices in the form of counter-rotating vortex pairs. The influence of non-uniform inflow on the performance of the pump may be caused by the non-uniform pressure field. For power fluctuations during reactor operations, this non-uniform pressure distribution may generate a low-pressure region on the impeller, which induces cavitation. The non-uniform inflow shown by inhomogeneous vectors was evaluated statistically through the turbulent kinetic energy, which represents the velocity variance in each direction. For a constant head, the non-uniformity of the flow field increased with the flow rate, and the scale of small-scale turbulent vortices decreased. With proper orthogonal decomposition analysis, 90% of the energy region and flow structures were dominated by the previous 412 modes. Furthermore, the temporal modes 1, 2, 3, 100, 200, and 400 show that the frequency of large-scale eddy turnover was about 6.6–13.2 Hz. However, the large-scale eddy could be characterized within the first mode of the spatial distribution.

Overdriven Detonation Velocity Dependence on Front Curvature

Overdriven detonation is a forced detonation where the shock state is stronger than the CJ state of the explosive. Overdriven detonations are usually not steady but decaying towards the CJ state. It is however possible to have a steady overdriven detonation wave when the wave forcing agent is steady. For sub-CJ curved and steady detonations it is known that detonation velocity (D) is a decreasing function of front curvature (k). This D(k) relation is often used in an approximate and an efficient procedure, known as Detonation Shock Dynamics (DSD), to calculate the propagation of a quasi-steady curved detonation front, without having to solve the entire flow field behind it. In real situations, a divergent front going around an obstacle may become convergent (negative curvature). To tackle this part of the front propagation, people using DSD extrapolate the D(k) curve into the negative curvature region. Matignon et al. [2] performed a test in which they created a steady overdriven detonation with a negative curvature in an explosive rod. The forcing agent was a stronger explosive cylinder wrapped around the tested rod. In this way they were able to measure a point on the D(k) plane above the CJ velocity, to which they extrapolated the usual D(k) curve. Here we raise the question of the uniqueness of this extrapolated curve. It is hard to answer this question experimentally, as candidates to replace the outer explosive are hard to find. But as we show here, it is quite easy to answer this question computationally. We use our reactant temperature dependent reactive flow model TDRR [3-5], which we have calibrated and validated from many test results. As a forcing agent we put a travelling pressure boundary condition on the test rod. We change independently the pressure P and the travelling wave speed D, and in this way, we are able to obtain points on the D(k) plane for negative curvatures and above the CJ state. We show that these points do not fall on a single D(k) curve, and conclude that there is no unique D(k) relation for overdriven steady detonations.

Influence of Different Reflux Groove Structures on the Flow Characteristics of the Roots Pump

A Roots pump often exhibits the typical characteristics of high gas pressure in the exhaust port, low pressure at a basic volume and large airflow pulsation at the outlet as a result of gas reflux. In light of this, this study employed Pumplinx software for the numerical calculation of the entire flow field of a two-bladed Roots pump. The effects of the rectangular and curved reflux groove structures on the internal flow field of a Roots pump, especially on the outlet pressure pulsation and flow rate, were unveiled separately. The rectangular reflux groove controlled the angle and thickness, while the curved reflux groove regulated the coordinates of the key points on the Bezier curve. It is worth recognizing that different reflux groove structures were not noticeable in enhancing the inlet measurement flow pattern; reduce the exhaust pressure pulsation, flow pulsation and exhaust section vortex. Interestingly, the rectangular return groove far outweighed the curved groove when optimizing the pressure and flow pulsation when registering the higher flow loss compared to the curved return groove. The merits and demerits of the Q criterion and omega criterion in characterizing the vortex structure of the flow field in the Roots pump were compared by Tecplot software. The omega criterion looked more robust, clear and continuous in revealing the strong and weak vortices in the Roots pump. The outcome of this research work could provide a reference for the study of Roots pump airflow pulsation, vortex analysis and casing structure design optimization.

Experimental study of flow visualisation using fluorescent dye

Flow visualisation is an important and effective tool in the study of fluid dynamics as it is able to provide a quick visible presentation and qualitative and quantitative description of the entire real-time flow field of an unsteady flow. Some flow visualisation techniques have been used in a wide range of industries. Flow visualisation using a fluorescent dye is an effective technique to qualitatively investigate flow patterns for various configurations which usually involve low flow velocities and small lab scale geometries. In the present study, a Kármán vortex street flow at the Reynolds number of about 2520 was chosen to be visualised to investigate the performance of various dye types (fluorescein dye, rhodamine B dye, and blue food dye), dye tracer concentrations, and injection nozzle sizes, and post-processing techniques were used to extract quantitative pixel intensity data from the obtained flow pattern images. The analysis showed that the image intensity of the dye in the flow is dependent on the concentration and injection nozzle size. Visualisation results for 60 different arrangements were presented and analysed to ultimately conclude the superiority of fluorescein dye at a concentration of 1250 mg/L, for the flow visualisation considered. Additionally, it was found that the injection nozzles with the diameters of 0.51 mm and 0.9 mm allowed for a precise and natural release of dye into the inlet flow where the flow pattern was clearly presented downstream of the geometry. These outcomes provide some new and additional experimental evidences and data for the improvement of flow visualisation techniques.

Particle Image Velocimetry Measurements in Accelerated, Transonic Wake Flows

This paper reports on particle image velocimetry (PIV) measurements in compressible accelerated wake flows generated by two different central injector types, which are mounted in a convergent-divergent nozzle. The injectors differ by the extent of their trailing edge located either in the subsonic (injector A) or supersonic flow region (injector B). In addition, the undisturbed nozzle flow without injector is studied as a reference case. The PIV results reveal typical wake flow structures expected in subsonic (injector A) and supersonic (injector B) wake flows. They further show that the Reynolds stresses mathrm {Re_{xx}} and mathrm {Re_{yy}} significantly decay in all three cases due to the strong acceleration throughout the nozzle. Interestingly, in the case of injector A, the flow stays non-isotropic with mathrm {Re_{yy}}>mathrm {Re_{xx}} also far downstream in the supersonic flow region. These measurements were motivated by the lack of velocity data needed to validate numerical simulations. That is why this paper additionally contains results from (unsteady) Reynolds-averaged Navier-Stokes ((U)RANS) simulations of the two wake flows investigated experimentally. The URANS simulation of the injector A case is able to accurately predict the entire flow field and periodic fluctuations at the wake centerline. However, in the case of injector B, the RANS simulation underestimates the far wake centerline velocity by about 4%.

Propagation of ionizing shock wave in a dusty gas medium under the influence of gravitational and azimuthal magnetic fields

In this paper, a closed-form solution for an ionizing spherical shock/blast wave in a dusty gas (a mixture of an ideal gas and solid particles of micrometer size) under the influence of gravitational and azimuthal magnetic fields is derived. In the dusty gas mixture, the solid particles are continuously distributed, and the equilibrium flow condition holds in the entire flow field region. Analytical solutions in the closed form for the first-order approximation are derived for adiabatic and isothermal flows. Furthermore, for the second approximation, the set of ordinary differential equations is derived. The influence of problem parameters, such as the ratio of the density of the solid particles to the initial density of the ideal gas, the gravitational parameter, the solid particles mass concentration in the mixture, adiabatic index, and Alfvén-Mach number on the peak pressure on the blast wave, on physical variables and the damage radius of the blast wave is studied for the first-order approximation. Our closed-form solution for the first-order approximation in the case of adiabatic flow is analogous to Taylor's solution in the case of a strong explosion-generated blast wave. It is shown that the damage radius of the blast wave and the peak pressure on the blast wave both decrease with the addition of dust particles, and hence, the shock/blast wave strength decreases. It is observed that in the whole flow field region, the quantity J0 increases with an increase in the Alfvén-Mach number value, and hence, the shock decay with an increase in the Alfvén-Mach number.

A hybrid Lagrangian–Eulerian flow solver applied to elastically mounted cylinders in tandem arrangement

The fluid–structure interaction of cylinders in tandem arrangement is used as validation basis of a multi-domain Lagrangian–Eulerian hybrid flow solver. The solver is built on a Lagrangian approximation of the entire flow-field using particles, in which grid based Eulerian flow solutions are overlaid, one for every solid body. The Eulerian grids are body fitted but of limited width and may overlap in cases of close proximity of the bodies. The Eulerian and Lagrangian solutions are strongly (implicitly) interconnected in two ways: The Lagrangian solution provides the conditions over the outer boundaries of the Eulerian grids, while the Eulerian solutions update the flow properties of the particles that are within their own domains. Also, implicit is the coupling of the solver with the structural dynamics in case the cylinders are elastically supported. The Lagrangian solver is based on the density–dilatation–vorticity–pressure formulation and makes use of the Particle Mesh method to obtain the flow velocity field while the Eulerian one on the density–velocity–pressure formulation. The hybrid solver is first validated in the case of an isolated rigid cylinder at Re=100. Then the case of a single elastically mounted cylinder at Re=200 is considered, followed by the case of two cylinders in tandem arrangement that are either rigid or elastically mounted. Good agreement with results produced with spectral element and immersed boundary methods is found indicating the capabilities of the hybrid predictions. Also the flexibility of the method in handling complex multi-body fluid–structure interaction problems is demonstrated by allowing grid-overlapping.