Specific Dissipation Rate Research Articles

Local-Variable-Based Transition Model for Hypersonic Flows Considering Wall Mass Injection

Pyrolysis gas injection during the ablation process will affect the hypersonic boundary-layer transition. This paper proposes a three-equation γ-Reθ-fb transition model that considers wall mass injection. First, the boundary conditions of wall mass injection are established and verified. Second, based on analysis of the compressible boundary-layer solutions under wall mass injection, new transition correlations are developed. This allows an injection factor transport equation to be constructed using strictly local variables, and this equation is coupled with the γ-Reθ transition model. Additionally, to model the wall mass injection effects in the fully turbulent zone, the wall boundary conditions for the specific turbulence dissipation rate are amended. The results of numerical simulations show that the transition onset locations and the changes in the heat transfer rate are reasonably consistent with experimental data.

A new non‐equilibrium modification of the k−ω$$ k-\omega $$ turbulence model for supersonic turbulent flows with transverse jet

AbstractThe goal of this research is to propose a new modification of a non‐equilibrium effect in the turbulence model to better predict high‐speed turbulent flows. For that, the two local compressibility coefficients are included in the balance production/dissipation terms in a specific dissipation rate equation. The specific dissipation rate reacts to changes in the local Mach number and density through these local coefficients. The developed model is applied to the numerical simulation of the spatial supersonic turbulent airflow with round hydrogen injection. In that, the effects of the proposed turbulence model on the flow field behavior (shock wave and vortex formations, shock wave/boundary layer interaction, and mixture layer) are studied via the solution of three‐dimensional Favre‐averaged Navier–Stokes equations with a third‐order Essentially Non‐Oscillatory scheme. A series of numerical experiments are performed, in which an allowable range of local constants by comparing results with experimental data is obtained. The non‐equilibrium modification by simultaneous decrease of the turbulence kinetic energy and increase of the specific dissipation rate gives a good agreement of the hydrogen depth penetration with experimental data. Also, the numerical experiment of the supersonic airflow with a nitrogen jet shows wall pressure distribution is consistent well with experimental data.

Analysis of informativeness of features of classification of dangerous weather events based on radar observation results

One of the crucial factors affecting the safety and regularity of state and civil aviation flights is the meteorological situation. The European territory of Russia is most characterized by dangerous meteorological phenomena associated with cumulonimbus clouds: shower, thunderstorms, hail, accompanied by high atmospheric turbulence. Currently, meteorological radar stations are an indispensable source of information about the weather situation for air transport. The criteria for the classification of meteorological phenomena used in modern radar stations are formed for each event separately and are based on knowledge only about the altitude distribution of radar reflectivity and air temperature, despite the fact that radar data assess the wind characteristics of the atmosphere. It is shown that optimization of the classification criteria for the mentioned meteorological phenomena should be realized by generalization of the criteria and their construction in accordance with the theory of statistical hypothesis distinction, as well as by additional use of information on atmospheric turbulence. Based on the analysis of radar signals reflected from the meteorological events of shower, thunderstorm, and hail, probability distributions of reflectivity and specific dissipation rate of turbulent energy were obtained. Statistical analysis of probability distribution densities was carried out for: the maximum value of reflectivity Zmax, its dependence on height H(Zmax), as well as the maximum specific dissipation rate of turbulent energy EDRmax and the value H(EDRmax). The classification criterion based on the maximum probability functional was chosen to determine the structure of classification algorithms and decision rules. At the same time under the acceptable confidence is accepted the value of the probability of correct classification not lower than 0.8. For the accepted criterion the decision thresholds are constructed and the complete matrices of classification probabilities are calculated. The results of calculations showed that the worst informativeness in the classification of dangerous meteorological events of cumulonimbus cloudiness have parameters H(Zmax), H(EDRmax). Parameters Zmax, EDRmax have greater separating ability, but even for them the confidence of classification is unacceptable. In the article to increase the confidence of classification the joint use of features in the form of multivariate probability distribution densities of information parameters was applied. The best results are achieved when three p(Zmax,H(Zmax),EDRmax) and four p(Zmax,H(Zmax),EDRmax,H(EDRmax)) features are used. In the probability matrices for these cases, the maximum and acceptable at 0.8 level of probabilities of correct classification are achieved. Thus, the expansion of the feature space due to atmospheric turbulence is justified in the problem under consideration. These results will be refined with increasing observation time and will vary for different climatic zones. In general, the decision thresholds for classifying dangerous meteorological events of cumulonimbus cloudiness should be adaptive.

Study of implicit CFD modeling of riblets on wind turbine airfoil in transitional flow

The study introduces a novel hybrid boundary condition, derived from existing literature, crafted for predicting the impact of riblets on airfoils in transitional flow. In contrast to models tailored for fully turbulent flow, the hybrid approach successfully captures the operational dynamics of riblets, as demonstrated through meticulous testing. The boundary condition integrates slip length and a modified specific dissipation rate (ω) boundary to encompass the entire riblet regime. Adjusting the model to match measured drag behavior enables predictions of riblet effects at higher Reynolds numbers pertinent to wind turbine blades. Validation reveals the model’s proficiency in capturing the order of magnitude in drag reduction and aligns the change in drag in the correct direction for diverse riblet heights, yet highlights discrepancies in replicating absolute drag reduction values, particularly at smaller angles of attack. This underscores the imperative for further refinement and tuning, necessitating additional experimental data at higher Reynolds numbers and across various angles of attack to ensure the model’s robust applicability across a broader spectrum of conditions.

Numerical modeling of hydrodynamics of spouted bed in solid fuel boiler

The issues of numerical modeling of hydrodynamics of a spouted fuel bed in the furnace of a solid-fuel boiler are considered. At present, solid-fuel boilers are widely used in the power industry of the Russian Federation, with the share of coal-fired generation to remain significant in the projected terms. Therefore, the study of the efficiency of thermal and hydrodynamic processes that ensure the implementation of clean coal technologies is a relevant task both today and in the long term. The article presents the following main stages of numerical modelling of the hydrodynamics of the spouted bed: problem formulation with selection of boundary and initial conditions, methods of solving the Navier-Stokes and continuity equations for the air flow, Newton's equations and diffusion equations for particles. The k-omega turbulence model was used in the calculations that is described by means of two partial differential equations for the variables k (kinetic energy of turbulence) and omega (specific dissipation rate). A comparative analysis of environmental advantages and disadvantages of existing methods of combustion of low-grade coal in schemes with in-cycle gasification (ICG) is carried out. Advantages and difficulties of switching to structures with CFB in the spouted bed mode are shown. Numerical modeling of the cold spouted bed created by means of particle injection is performed, a set of initial settings and boundary conditions is presented, the adequacy of the obtained results is verified by hydrodynamic characteristics of the isothermal process. The obtained results allow us to proceed to the next stages with non-isothermal models, with heat exchange and combustion reactions in the spouted bed of coal taken into account. The following refinement of the physical model will allow to achieve more accurate and reliable results and to ensure their correct scaling.

Data-driven discovery of turbulent flow equations using physics-informed neural networks

In the field of fluid mechanics, traditional turbulence models such as those based on Reynolds-averaged Navier–Stokes (RANS) equations play a crucial role in solving numerous problems. However, their accuracy in complex scenarios is often limited due to inherent assumptions and approximations, as well as imprecise coefficients in the turbulence model equations. Addressing these challenges, our research introduces an innovative approach employing physics-informed neural networks (PINNs) to optimize the parameters of the standard k−ω turbulence model. PINNs integrate physical loss functions into the model, enabling the adaptation of all coefficients in the standard k−ω model as trainable parameters. This novel methodology significantly enhances the accuracy and efficiency of turbulent flow simulations, as demonstrated by our application to the flow over periodic hills. The two coefficients that have been modified considerably are σω and α, which correspond to the diffusion and production terms in the specific dissipation rate equation. The results indicate that the RANS simulation with PINNs coefficients (k−ω−PINNs simulation) improves the prediction of separation in the near-wall region and mitigates the overestimation of turbulent kinetic energy compared to the base RANS simulation. This research marks a significant advancement in turbulence modeling, showcasing the potential of PINNs in parameter identification and optimization in fluid mechanics.

CFD assessment of RANS turbulence modeling for solidification in internal flows against experiments and higher fidelity LBM-LES phase change model

Generation-IV nuclear reactors’ potential coolant candidates include molten salts and liquid metals. Owing to their high melting temperature, both the design and safety assessments of these reactors need to take into consideration potential solidification events during normal or abnormal operation. This work assesses the Finite Volume Computational Fluid Dynamics (FV-CFD) enthalpy-porosity method combined with the Reynolds Averaged Navier Stokes (RANS) model k−ω to model internal solidification under turbulent flow conditions for high and low Prandtl numbers at a moderate computational cost, which is required for full-core nuclear reactor analyses. Concerning high Prandtl numbers, the predictions of macroscopic quantities generated by the FV-CFD RANS model are contrasted against a well-known internal solidification experiment on water (Thomason et al., 1978). A key factor in the satisfactory agreement between the CFD RANS model and the experiment is the addition of an interface turbulence-damping source to the specific dissipation rate equation (ω). For the low Prandtl numbers involved in liquid metals, there is a lack of high-fidelity experiments due to the complicated measurements. Thus, to perform the FV-CFD RANS model assessment, we develop and validate a high-fidelity phase-change model based on the Lattice Boltzmann Method (LBM) with a Large Eddy Simulation (LES) turbulence model. To the author’s knowledge, this is the first attempt to integrate LES turbulence models with phase-change solidification in the LBM context. Considering the computational time advantage of the FV-CFD RANS model over higher fidelity models and the good agreement of its predictions against experiments and the LES model demonstrated, this work demonstrates that FV-CFD RANS is an attractive tool to model internal turbulent solidification.

Progressive augmentation of turbulence models for flow separation by multi-case computational fluid dynamics driven surrogate optimization

In the field of data-driven turbulence modeling, the consistency of the a posteriori results and generalizability are the most critical aspects of new models. In this study, we combine a multi-case surrogate optimization technique with a progressive augmentation approach to enhance the performance of the popular k−ω shear stress transport (SST) turbulence model in the prediction of flow separation. We introduce a separation factor into the transport equation of a turbulent specific dissipation rate (ω) to correct the underestimation of the turbulent viscosity by the k−ω SST model in the case of flow separation for two-dimensional cases. The new model is optimized based on their performance on the training cases including periodic hills and curved backward-facing step flow. Simulation of the channel flow is likewise included in the optimization process to guarantee that the original performance of k−ω SST is preserved in the absence of separation. The new model is verified on multiple unseen cases with different Reynolds numbers and geometries. Results show a significant improvement in the prediction of the recirculation zone, velocity components, and distribution of the friction coefficient in both training and testing cases, where flow separation is expected. The performance of the new models on the test case with no separation shows that they preserve the successful performance of k−ω SST when flow separation is not expected.

Hydrodynamics of LIMPET type OWC device under Stokes second-order waves

This research aims to investigate the hydrodynamic performance and efficiency of the LIMPET oscillating water column (OWC) device. A two-dimensional numerical wave tank (NWT) is used in a fully nonlinear Reynolds averaged Navier–Stokes equations (RANS) model with the k−ω turbulence model for the Stokes second-order incident waves. A volume of fluid (VOF) method is utilized to capture the free surface elevation. The numerical simulation shows qualitative velocity vector and streamline profiles inside the chamber of the LIMPET OWC device across a whole pressure fluctuation cycle. It is found that the fluid particles with smaller velocity magnitudes are distributed throughout all directions, whereas the fluid particles with larger velocity magnitudes are aligned in one direction close to the orifice of the OWC device. Higher incident wave heights promote the additional vortex generation at the lower tip of the front wall of the device chamber. The specific dissipation rate is considerably higher as incident wave heights become higher, which demonstrates that the wave energy dissipation is higher for higher incident wave heights. The power produced by the LIMPET OWC device is higher for the incident waves having higher incident wave heights. In contrast, the efficiency of the OWC device depends on various parameters like incident wave height, water depth to wavelength ratio, pneumatic damping coefficients, etc.

Revisiting RANS prediction of transitional flow on T3A flat plate subject to various freestream turbulences

A laminar–turbulent transition subject to a freestream turbulence involves highly complex flow mechanisms, which have received considerable interest in the past decades. Accurately predicting such complex physical phenomena is significantly challenging using computational fluid dynamics solvers, particularly in industrial engineering applications. In this study, the capability of two transitional turbulence models—k−kl−ω and k−ω−γ−Re˜θt—to predict a T3A plate transition scenario was revisited. First, the predicted boundary layer data was compared to ERCOFTAC experimental measurements. Subsequently, a transitional flow subject to constant and sinusoidal freestream turbulences was systematically investigated. Under a constant freestream turbulence, the two models exhibited opposite tendencies of the transition starting and ending positions with the increase in Refst. However, there were still some similarities between the results of the two models. When the length scale was fixed, the transition area moved upstream with increasing turbulence intensity. The transition zone was more sensitive to a small length scale than to a considerable length scale. The dynamic boundary layer under the sinusoidal combination condition was less disturbed than the sinusoidal turbulence intensity and the sinusoidal specific turbulence dissipation rate. Regardless of the type of sinusoidal freestream turbulence the boundary layer was exposed to, increasing the oscillation frequency significantly disturbed the transitional flow. It was observed that the inertia effect of the dynamic onset point was enhanced by increasing the oscillation frequency. Concurrently, a significant phase delay occurred, and the delay time was approximately proportional to the oscillation frequency. The extreme position of the transition onset close to the leading edge of the plate was not affected by the oscillation frequency, whereas it depended on the sinusoidal variable. However, the extreme downstream transition onset point was significantly affected by the oscillation frequency.

On the turbulence modelling of waves breaking on a vertical pile

Incipient wave breaking on a vertical circular pile is simulated with a Reynolds stress– $\omega$ turbulence model. Comparison of results simulated with a stabilized two-equation turbulence model, as well as no turbulence model, demonstrates that the breaking point and the peak force on a vertical cylinder due to incipient breaking should not be affected by the turbulence closure model, provided that it is stable and the simulations are converged. Notably, the present results show that the build-up to peak force induced by incipient wave breaking can be accurately predicted without any turbulence closure model. However, for the prediction of the secondary load cycle (SLC), proper turbulence modelling is required, as this process involves both turbulence production and lee-side flow separation. The Reynolds stress– $\omega$ model is demonstrated to predict the SLC more accurately than a stabilized two-equation $k$ – $\omega$ turbulence model, as the flow separation points and vorticity field are better predicted. Some existing studies indicate that the generation of the SLC does not necessarily result from flow separation, but is rather due to the suction force. The present work finds that the occurrence and point of flow separation significantly affect the magnitude of the suction force, which hence affects the SLC prediction significantly. For waves breaking on a vertical pile, proper turbulence modelling is therefore essential for accurate SLC predictions. (In the above, $k$ is the turbulent kinetic energy density and $\omega$ is the specific dissipation rate.)

Numerical Evaluation of Riblet Drag Reduction on a MALE UAV

Flow control methods for aerodynamic drag reduction have been a field of interest to aircraft designers, who seek to minimize fuel consumption and increase the aircraft’s aerodynamic performance. Various flow control techniques, applied to aeronautical applications ranging from large airliners to small hand-launched unmanned aerial vehicles (UAVs), have been conceptualized, designed and tested in the past. Among others, the concept of riblets, inspired by the shark’s skin morphology, has been proposed and evaluated for airliners. In this work, the implementation of riblets on a medium-altitude long-endurance UAV (MALE) is investigated. The riblets can offer drag reduction due to the decrease in total skin friction, by altering the boundary layer characteristics in the near-wall region. The riblets are implemented on specific locations on the UAV (main wing, fuselage and empennage) and appropriately selected, on which the boundary layer becomes transitional from the laminar to the turbulent flow regime. For this reason, computational fluid dynamics modelling is performed by solving the Reynolds-averaged Navier–Stokes equations, incorporating the k-ω SST eddy viscosity turbulence model. The effect of the riblets in the near-wall region is modelled with the use of an appropriate wall boundary condition for the specific turbulence dissipation rate transport equation. It is shown that a drag reduction benefit, for both the loiter and the cruise flight segments of the UAV mission, can be obtained, and this is clearly presented by the drag polar diagrams of the air vehicle. Finally, the potential benefit to flight performance in terms of endurance and payload weight increase is also evaluated.

Study and Simulation of the Thrust Vectoring in Supersonic Nozzles

The present study aims to numerically simulate the thrust vectoring by secondary injection. The analysis of flow for this study was done using ANSYS Fluent. The kω-sst turbulence model was used. The baseline solver was selected as a double-precision Density-based coupled solve with implicit time integration. Least squares cell-based spatial discretization in which the solution was assumed to vary linearly was used and a second-order upwind scheme is used for interpolating the values of pressure, momentum, turbulent kinetic energy, specific dissipation rate, and energy. The computational analysis was conducted under study conditions. The initialization for the steady-state problem was done using full multigrid (FMG) initialization to get the initial solution and the boundary was provided to get the reference value. The results of the study with and without fluid injection are presented in terms of pressure, angle of deflection, and efficiency. These results are then compared with those obtained numerically or experimentally by other authors. This comparison was very interesting and the results were very close, the error was only 5%.

Reynolds stress turbulence modelling of surf zone breaking waves

Computational fluid dynamics is increasingly used to investigate the inherently complicated phenomenon of wave breaking. To date, however, no single model has proved capable of accurately simulating the breaking process across the entirety of the surf zone for both spilling and plunging breakers. The present study newly considers the Reynolds stress–$\omega$turbulence closure model for this purpose, where$\omega$is the specific dissipation rate. Novel stability analysis proves that, unlike two-equation closures (at least in their standard forms), the stress–$\omega$model is neutrally stable in the idealized potential flow region beneath surface waves. It thus naturally avoids unphysical exponential growth of turbulence prior to breaking, which has plagued numerous prior studies. The analysis is confirmed through simulation of a progressive surface wave train. The stress–$\omega$model is then applied to simulate a turbulent wave boundary layer, demonstrating superior accuracy relative to a two-equation model, especially during flow deceleration. Finally, the stress–$\omega$model is employed to simulate spilling and plunging breaking waves, with seemingly unprecedented accuracy. Specifically, the present work marks the first time that a single turbulence closure model collectively: (1) avoids turbulence over-production prior to breaking, (2) accurately predicts the breaking point, (3) provides reasonable evolution of turbulent normal stresses, while also (4) yielding accurate evolution of undertow velocity structure and magnitude across the surf zone, for both spilling and plunging cases. Differences in the predicted Reynolds shear stresses (hence flow resistance) are identified as key to the improved inner surf zone performance, relative to a state-of-the-art two-equation model.

Reynolds Stress Turbulence Modelling with γ Transition Model

Implementation of the SSG/LRR-ω-γ model is carried out in the current study to predict transition to turbulence. The framework uses a Reynolds stress transport model, SSG/LRR-ω, as the base turbulence formulation and is coupled with Menter's γ transition model. To extend its applicability to different transition mechanisms, the production terms in the Reynolds stress and specific dissipation rate transport equations are modified. SSG/LRR-ω-γ uses simplified correlations that do not depend on freestream quantities, making it coordinate independent and rendering it Galilean invariant. Additionally, using a second-order closure turbulence model makes it suitable for complex flow fields. The influence of different grid parameters on the model is also discussed. A validation study is performed using multiple benchmark flat plate cases as well as 2D and 3D geometries to demonstrate the model's capability in predicting different transition mechanisms. When compared to state-of-the-art transition models, the proposed model shows equivalent or higher predictive capability.

Conjugate heat transfer numerical study of the ejector by means of SU2 solver

In this paper, the test supersonic ejector with conjugate heat transfer in solid bodies has been studied numerically. An extensive numerical campaign by means of open-source SU2 solver is performed to analyze the fluid dynamics of the ejector flowfield accounting for the heat conduction in solids. The fluid domain simulation is carried out by employing compressible RANS treatment whilst the heat distribution in solids is predicted by simultaneous solving the steady heat conduction equation. The working fluid is R245fa and all simulations are performed accounting for real gas properties of the refrigerant. Experimental data against numerical results comparison showed close agreement both in terms mass flow rates and static pressure distribution along the walls. Within the CFD trials, the most valuable flow parameters at a wall vicinity are compared: distribution across the boundary layer of the temperature and the turbulent kinetic energy specific dissipation rate, boundary layer displacement and momentum thicknesses. A comprehensive analysis of the simulation results cases with adiabatic walls against cases with heat permeable walls revealed the actual differences of the flow properties in the wall vicinity. However, the ejector performance has not changed noticeably while accounting for the heat conduction in solids.

Analysis of Flow Characteristics and Effects of Turbulence Models for the Butterfly Valve

In the present study, the flow characteristics of butterfly valves with different sizes DN 80 (nominal diameter: 76.2 mm), DN 262 (nominal diameter: 254 mm), DN 400 (nominal diameter: 406 mm) were numerically investigated under different valve opening percentages. Representative two-equation turbulence models of two-equation k-epsilon model of Launder and Sharma, two-equation k-omega model of Wilcox, and two-equation k-omega SST model of Menter were selected. Flow characteristics of butterfly valves were examined to determine turbulence model effects. It was determined that increasing turbulence effect could cause many discrepancies between turbulence models, especially in areas with large pressure drop and velocity increase. In addition, sensitivity analysis of flow properties was conducted to determine the effect of constants used in each turbulence model. It was observed that the most sensitive flow properties were turbulence dissipation rate (Epsilon) for the k-epsilon turbulence model and turbulence specific dissipation rate (Omega) for the k-omega turbulence model.

Boundary-layer transition model for icing simulations of rotating wind turbine blades

Icing simulations for wind turbine blades should consider the roughness-induced flow transition. Adding a transport equation for ‘roughness amplification’ to the Langtry-Menter model, the roughness-induced transition can be predicted for rough flat plates. However, this approach exhibits a limitation that it cannot predict the skin friction in the shadow zone of blunt bodies. Such an approach depends on the boundary condition(s) of specific dissipation rate (ω). Typically boundary conditions for turbulent kinetic energy (k) and ω have been investigated for various roughness heights, but have been applied only for fully turbulent conditions. This study introduces an approach to predict the flow transition and the skin friction for a roughened surface, whereby the Langtry-Menter model including roughness amplification is coupled with the k and ω boundary conditions. The proposed method shows good agreement with the experiments for turbulent onset and the distributions of skin friction and heat convection for a roughened flat plate and a circular cylinder. Using the turbulent models under fully turbulent and transitional assumptions, the effects of the flow transition on the ice accretion shape on a rotating wind turbine are compared. The modified turbulent model showed better performance for the icing simulations without any tuning.

Constructal design of different ribs for thermo-fluid performance enhancement of a solar air heater (SAH)

In this paper, the constructal theory has been applied to evolve six new types of ribs (T-rib, left arm inclined T-rib, right arm inclined T-rib, Y-rib, concave and convex T-ribs) for a solar air heater (SAH). The fluid flow and heat transfer characteristics of the SAH with these ribs have been numerically investigated by solving the mass, momentum, energy, and turbulence equations employing the finite volume technique of ANSYS Fluent R16. The SST k−ωmodel has been used to solve the turbulence quantities, especially, the turbulent kinetic energy (k), and the specific dissipation rate (ω). The performance of the SAH has been obtained by varying different prominienet parameters of importance, such as the pitch (20 mm–90 mm), stem height (3 mm–11 mm), the inclination angle of the rib (0o-60°) and Reynolds number (5000–18,000). The optimal lengths for the pitch (i.e., 80 mm) and for the stem height (i.e., 8 mm) have been found out for T-ribs. It has been observed that the Nusselt number for T-rib increases by 191% in a range of Reynolds number, 5000–18,000, and at the optimum pitch and stem height. It is also observed that the Nusselt number marginally increases with the inclination angle of the rib. The concave T-rib and convex T-ribs have been evolved from the basic T-rib. Among all the considered ribs, the T-rib is found to be the best heat transfer enhancer keeping the friction factor at a low value. We found a higher Nusselt number and a lower friction factor for the present SAH with the T-ribs, as compared to that of the SAHs considered by previous researchers. The thermo-hydraulic performance (THPP) of a SAH with present rib (i.e., T-rib or the concave T-rib) has been observed to be more than SAH with other shapes of ribs used by previous researchers.

Turbulent flow in a square cross-sectioned bubble column computed by a scale-resolving Reynolds-stress model

The present study focuses on the computations of turbulent flow in a square cross-sectioned bubble column by utilizing the two-fluid model (TFM) in conjunction with advanced Reynolds-stress models (RSMs) within the Unsteady Reynolds-averaged Navier–Stokes (URANS) framework. The use of such an advanced modeling approach in combination with the TFM, rarely employed for two-phase flow computations, is motivated by its inherent capability of resolving both Reynolds-stress anisotropy and stress-dissipation anisotropy, also of the corresponding residual turbulence. The presently adopted RSMs are based on the formulation proposed initially by Jakirlić and Hanjalić (2002) for incompressible single-phase flows. Two different RSM versions (Jakirlić and Maduta (2015)), both based on the homogeneous dissipation (εh) concept that employs the specific dissipation rate (ωh=εh/k) as the length-scale-determining variable, are applied in the present work. The baseline model version is formulated within the conventional RANS framework, whereas the advanced model represents an instability-sensitized, eddy-resolving RSM variant, capable of adequately capturing the fluctuating turbulent motion in accordance with the SAS methodology (Scale-Adaptive Simulation) proposed by Menter and Egorov (2010). The results obtained by both RSMs are discussed along with the corresponding experimental database made available by Deen and co-workers (Deen et al., 2000, 2001; Deen, 2001). Additionally, the most-widely used modeling approach for two-phase flows is followed by utilizing the Standard high-Reynolds number k-ε model for the purpose of a comparative assessment. Furthermore, both RANS models are extended by two different proposals for a model term accounting for the so-called bubble-induced turbulence (BIT). The model equations are implemented into the open source software OpenFOAM® based on the finite-volume method on unstructured meshes. The results obtained exhibit high level of agreement with the experimental reference demonstrating high potential of both Reynolds-stress models in computing the bubbly flows. This relates in particular to the correspondingly captured resolved turbulence intensity in this bubble-plume-induced unstable flow event, leading subsequently to a correctly returned velocity field. The mean flow asymmetry, characterizing the baseline Eddy-Viscosity Model (EVM) performance was remedied only after introducing the BIT-related source term contributing appropriately to intensified turbulence production.