Subcritical Flow Research Articles

Hybrid wave/current energy harvesting with a flexible piezoelectric plate

We investigate the dynamics and energy production capability of a flexible piezoelectric plate submerged close to the free surface and exposed to incident head gravity waves and current. A theoretical model is derived in which the flag and its wake are represented with a vortex line while the body of the fluid is considered to be inviscid. The model is employed to describe the hydrodynamic interactions between a flexible plate, its wake, gravity incident waves and the current. The model reveals two distinct vibration states of a piezoelectric device corresponding to almost similar optimal energy production levels. The first is associated with the cantilever fluttering mode of the plate, with limited dependency on the plate's flexibility across different Froude numbers and incoming wave frequencies. The other resembles the flow-induced flapping mode in more flexible plates, with the energy output showing a higher dependency on plate flexibility. The concurrent existence of these two energetic modes allows adjustment of the plate length to consistently achieve the maximum energy production level across different flow conditions. The role of the Froude number of the system's responses is explored and correlated to the appearance of gravity wave groups on the surface, each propagating with a different wavenumber. It is shown that a submergence depth of less than half of the body length is required to reach a high energetic condition in subcritical and critical flows. Finally, the optimal inductive and resistive values are related to proper matching between flow, mechanical and electrical time scales.

Numerical simulation of subsonic flow around oscillating airfoil based on the Navier–Stokes equations

ABSTRACT Unsteady Reynolds-averaged Navier–Stokes equations of an incompressible fluid are used to numerically simulate the flow around an oscillating airfoil. A comparison is made between two differential one-equation turbulence models SA and SALSA on the problems of subcritical and supercritical turbulent incompressible flow around an oscillating NACA 0015 airfoil. The numerical algorithm utilized for solving the governing equations is founded upon a three-layer implicit scheme, which exhibits second-order integration accuracy in time, third order of upwind approximation of convective terms, and second-order symmetric approximation of the diffusion terms. Pressure and velocity field coupling is achieved through the implementation of the artificial compressibility approach, which is employed for the computation of unsteady problems. The system of initial equations is numerically integrated using the control volume method. The resulting system of algebraic equations has been solved by the GMRES method with ILU(k) preconditioning. The obtained instantaneous streamlines, vorticity contours, and hysteresis curves of unsteady airfoil aerodynamic loads are analyzed for cases of weak ( α 0 = 4 ° ), developed ( α 0 = 11 ° ) and massive ( α 0 = 15 ° ) flow separation at Reynolds number Re = 1.95 × 10 6 . In the case of weak flow separation, the values of the lift coefficient obtained using the SA and SALSA models differ from the experimental data by 10% and 5%, respectively. With a developed separation, these values are already equal to 10–20% for the SA model and 6–8% for the SALSA model. The average values of the lift coefficient, which are obtained using the SA and SALSA models, in the case of massive flow separation, differ from the experimental data by 50–60% and 10–15%, respectively. Comparing the calculation results with both known experimental and calculated data demonstrates that in flows with developed and massive flow separation, which are characterized by unsteady effects in turbulence, the SALSA turbulence model performs better than other tested models. The aerodynamic coefficients obtained with the SALSA turbulence model are in 10–15% better agreement with experimental data than those obtained with other turbulence models.

Assessment of Aerodynamic Plates Subjected to Von Kármán Vortex Street for Enhancing the Wind Energy Generation in Blade-Less Devices

This study explores the feasibility of using an oscillating plate downstream of a cylindrical body to produce mechanical energy from a Von Kármán vortex street under sub-critical flow conditions (Re = 72,500). The study aims to quantify the impact of the plate length, its separation from the cylinder, and a machine damping factor on the power coefficient and the blade’s displacement to identify the optimal configuration. This preliminary assessment assumes that the plate oscillation is small enough to avoid changes in the vortex dynamics. This assumption allows the construction of a surrogate model using Computational Fluid Dynamics (CFD) to evaluate the effect of plate length and separation from the cylinder on the fluctuating lift forces over the plate. Later, the surrogate model, combined with varying machine damping factors, facilitates the description of the device’s dynamics through the numerical integration of an angular momentum equation. The results showed that a plate with a length of 0.52D, a separation of 5.548D from the cylinder, and a damping factor of 0.013 achieved a power coefficient of 0.147 and a perpendicular displacement of 0.226D. These results demonstrate a substantial improvement in the performance of blade-less generators.

Reservoir characteristics and potential of a shallow-marine multi-level fan in the Miocene Huangliu Fm. within the DF1-1 gas field (Yinggehai Basin, S China)

Deep-marine fans receive much attention because of their high potential for hydrocarbon exploration. Shallow-marine fans are much rarer and less well investigated. Particularly the formation and reservoir distribution of shallow-marine multi-level submarine fans are still hardly understood. Integration of data from cores, well logs, 3D seismics, in combination with analyses of thin-sections, porosity and permeability of Member 1 of the Miocene Huangliu Formation in the DF1-1 Gas Field of the Yinggehai Basin (S China) has provided much new information on the characteristics, development, and hydrocarbon potential of the reservoirs in such a type of fan. The study indicates that the IIb Gas Level of this member is built of three 5th-order sequences. The fan consists of channels, levees, ‘overbank’ sand sheets, and pro-fan silt- and mudstones. The development of this fan was controlled mainly by alternating subcritical and supercritical gravity flows, sediments supply and relative sea-level fluctuations. The NW-SE running channels occur on three slightly different levels that form 3 zones with chutes-and-pools morphology, which results in a multi-level submarine fan with zones of different sand thickness. The sand content of the channels and sand sheets is commonly higher than 50%. The reservoir sands underwent intermediate compaction and show mainly primary intergranular pores with short contacts. The porosity is 13.7–19.5% and the permeability ranges from 3.2 to 14.2 mD. The best reservoirs are the sand sheets, followed by channel sediments. The various reservoirs are commonly not interconnected due to lithological and stratigraphic traps. A new reservoir distribution model of submarine fans could thus be developed, which will facilitate oil and gas exploration.

Properties and Model of a Lacustrine Shale Oil Reservoir: A Case Study of the Upper Fourth Member and Lower Third Member of the Shahejie Formation in Dongying Sag and Zhanhua Sag, Jiyang Depression

By combining thermal simulation experiments with core data, thin sections, scanning electron microscopy (SEM), source rock, and high-pressure mercury and gas adsorption analysis, this paper evaluates the properties and models of shale reservoirs in the upper fourth member and the lower third member of the Shahejie Formation in Dongying Sag and Zhanhua Sag. The results show that the oil shale is a high-quality source rock with petroleum generation potential. Inorganic mineral pores, organic pores, and fractures have developed with petroleum storage capacity. Clay and organic-rich soft shale lithofacies are interbedded with carbonate-rich hard shale lithofacies to form sandwich-type source–reservoir–caprock assemblages with internal sealing properties. Bitumen occurs mostly in the free state, and to a lesser extent is adsorbed, and shows flow characteristics. The migration resistance of the bitumen is displacement pressure, including capillary force and adsorption resistance, and the main force is pore fluid pressure. The migration modes of the bitumen include both subcritical flow and instantaneous flow, which are controlled by pore fluid pressure, displacement pressure, and the rock’s fracture strength. Owing to the multi-scale characteristics of the shale reservoir space, a vein-type model of a multi-scale progressive transport network is developed that obeys Murray’s law with a dominant migration pathway in the shale reservoir. The shale oil reservoir is a special lithologic reservoir controlled by the sedimentary environment and has self-generation, self-storage, and self-sealing characteristics with developed pore fluid overpressure and a multi-scale transport network.

Hydraulic characteristics of flow at grid drop-type dissipators with the upstream supercritical approach flow

Through installing a grid drop-type dissipator at the edge of the vertical drops with an upstream supercritical approach flow, the present study investigates hydraulic characteristics of flow up- and downstream of the drop, based on model experimentation. Experiments were conducted on three different drop heights, considering eight different grid drop-type dissipators with certain grids dimensions. Results demonstrate that assembling this type of dissipator at the edge of a vertical drop increases the rate of energy dissipation up to about 70%, compared to a plain vertical drop. Owing to the increase in flow momentum and the falling jets’ collision with bottom of the downstream channel, for a given flow discharge, while the porosity of the grid drop-type dissipator is increased, the wetted length of the dissipator and the energy dissipation decrease; however, the length and depth of the pool at the drop base increase. The relative length of the pool is significantly affected by air entrainment, caused by the spaces between the separated falling jets. By increasing flow discharge, pressure fluctuations decrease and trend of the variation of average pressure becomes smoother. Although the former researchers reported a hydraulic jump downstream of the grid drop-type dissipators with an upstream subcritical approach flow, it was not the case in some tests of the present study with an upstream supercritical approach flow. Finally, based on statistical and error analyses, empirical relationships were derived to predict the flow hydraulic characteristics, to be used by design engineers in practice.

Monitoring Scour at Bridge Piers in Rivers with Supercritical Flows

Bridges crossing rivers wider than 50 m are typically supported by piers. In a mobile riverbed, scour occurs around bridge piers, and it is the main cause of bridge collapses worldwide, especially during floods. While bridge pier scour has been extensively studied, there is still a lack of measuring systems for scour monitoring in the field. In this paper, we present existing devices for scour measurement and analyze their comparative advantages and disadvantages. A study case with a scoured bridge pier in supercritical flow is presented. Results show that supercritical flow patterns previously reported at the laboratory scale also occur in the field. The measured scour supports the hypothesis that supercritical flows, even when having high flow speeds, do not produce higher scour than subcritical flows. A possible explanation linked with the sediment sizes of rivers with supercritical flows is discussed. Further, field measurements of scour around bridge piers are needed to enhance our understanding of this complex and nearly unexplored situation.

A coherent composite approach for the continuous circular hydraulic jump and vortex structure

We examine the structure of the continuous circular hydraulic jump and recirculation for a jet impinging on a disk. We use a composite mean-field thin-film approach consisting of subdividing the flow domain into three regions of increasing gravity strength: a developing boundary layer near impact, an intermediate supercritical viscous layer and a region comprising the jump and subcritical flow. Unlike existing models, the approach does not require any empirically or numerically adjusted boundary conditions. We demonstrate that the stress or corner singularity for a film draining at the edge is equivalent to an infinite slope of the film surface, which we impose as the downstream boundary condition. The model is validated against existing experiment and numerical simulation of the boundary-layer and Navier–Stokes equations. We find that the flow in the supercritical region remains insensitive to the change in gravity level but is greatly affected by viscosity. The existence of the jump is not necessarily commensurate with the presence of recirculation, which is strongly dependent on the upstream curvature and steepness of the jump.

Water surface response to turbulent flow over a backward-facing step

The water surface response to subcritical turbulent flow over a backward-facing step (BFS) is studied via high-resolution large-eddy simulation (LES). The LES method is validated first using data of previously reported experiments. The LES-predicted water surface is decomposed into different types of gravity waves as well as turbulence-driven forced waves. Analysis of the LES data reveals the interplay between low-frequency large-scale turbulence structures, which are the result of flow separation from the step and reattachment behind the step, and the dynamics of the water surface. The water surface deformation is mainly the result of freely propagating gravity waves and forced waves, owing to turbulence in the form of rollers and/or hairpin vortices. Gravity waves with zero group velocity define the characteristic spatial and temporal scales of the surface deformations at higher frequencies, while large eddies determine their low-frequency modulation. These deformations are mainly confined in lateral bands that propagate downstream following the advection of the near-surface streamwise vortices (rollers) that are shed from the step. Steeper surface waves are observed in regions of negative perturbation velocity gradient and down-welling, downstream of the larger rollers, and are associated with thin isolated regions of high vorticity near the surface. The investigation of such a complex flow has shown that the decomposition of the water surface fluctuations into its different physical components may be used to identify the dynamics of the underlying flow structure.

The viscoplastic circular hydraulic jump

We examine theoretically the spread of a jet impacting on a circular disk and the hydraulic jump of a viscoplastic fluid of the Herschel–Bulkley type. The depth-averaging approach is employed in the supercritical region, and the subcritical flow is assumed to be inertialess of the lubrication type. The jump is treated as a shock, where the balance of mass and momentum is established in the radial direction, including the effect of surface tension across the jump. We show that, in contrast to the Newtonian jet, which requires separate formulations in the developing-boundary layer and fully viscous layers, the supercritical formulation for the fully yielded and pseudo-plug layers is uniformly valid between the impingement zone and the jump. Consequently, a viscoplastic jet does not experience the discontinuity in the film height, pseudo-plug layer velocity gradient, and shear stress, exhibited by a Newtonian film at the transition location. The jump is found to occur closer to impingement, with growing height, as the yield stress increases; the subcritical region becomes invaded by the pseudo-plug layer. The viscosity does not influence sensibly the jump location and height except for small yield stress; only the yielded-layer is found to remain sensitive to the power-law rheology for any yield stress. In particular, shear thickening can cause the fully yielded layer to drop in height despite the jump in the film surface. We also find that the jump would not occur if the disk was smaller than a critical size, but the yield stress tends to enhance the formation of the jump compared to a Newtonian jet. We show that an almost constant local downstream Froude number also exists for a viscoplastic fluid. Finally, our results reduce to the limiting cases of Bingham, power-law, and Newtonian fluids.

Plunging Flow and Coherent Turbulent Structures in a Straight Pool‐Riffle

AbstractPool‐riffle units are naturally occurring topographical elements of rivers. Various hypotheses have been proposed to describe how the hydrodynamics in pool‐riffle units may lead to scour and sediment transport. However, most hypotheses have focused on time averaged properties, and a physical mechanism for observations of high near‐bed velocities has not been proposed. In this study, we apply Large Eddy Simulations to examine the dynamics of flow over straight riffles. We show that a high velocity core of fluid can alternately skim or plunge toward the bed as a function of the Froude number (Fr) at the crest of the riffle, even within a subcritical flow regime. Coherent turbulent structures are generated in the pool and induce high magnitude fluctuations of shear stress and bed pressure. Four different turbulent structures are described and the concept of vortex resistance is used to discuss how turbulence can induce the observed bifurcation in pool hydrodynamics. Despite the simple geometry, the hydraulic scaling means that the results provide a novel physical explanation of near‐bed high velocity flow observations in natural pool‐riffles. The results are also significant because turbulent shear stresses in the head of a pool exceed what occurs elsewhere in the channel, including the riffles. Further research should examine the conditions under which plunging flow may occur and turbulence may lead to sediment entrainment in other riffle pool geometries.

Scour around the single emergent cylinder due to subcritical and supercritical approach flow conditions

ABSTRACT Flume experiments with a uniform cohesionless sand with d 50 = 0.9 m m were utilized in the current study to examine the local scour process around a single emergent cylinder under various geometrical circumstances and with a various flow characteristic that simulates an inundating tsunami flow. This single emergent cylinder represents a piloti-type column located over a movable bed material because piloti-type columns are used to elevate the building structures from the ground level. In the experiments, it was noted that the maximum scour depth probably occurs at the cylinder’s upstream face, resembling local scour around a scaled-down bridge pier in an open channel. Additionally, the scour hole around the cylinder is shallower the smaller they are, as are the horseshoe vortices that surround them. Furthermore, the effects of the surface bow-wave, hydraulic jump detachment and the wall-jet over the front face of the emerging cylinder were used to identify the relationship concerning the scouring pattern and selected flow characteristics over a piloti-type emergent column under tsunami flow. Empirical formulae have been finally developed to determine the maximum scour depth in front of the cylinder, which is beneficial to characterize the stability of the piloti-type columns, considering the specified Froude number conditions.

Explaining the Lack of Mesh Convergence of Inviscid Adjoint Solutions near Solid Walls for Subcritical Flows

Numerical solutions to the adjoint Euler equations have been found to diverge with mesh refinement near walls for a variety of flow conditions and geometry configurations. The issue is reviewed, and an explanation is provided by comparing a numerical incompressible adjoint solution with an analytic adjoint solution, showing that the anomaly observed in numerical computations is caused by a divergence of the analytic solution at the wall. The singularity causing this divergence is of the same type as the well-known singularity along the incoming stagnation streamline, and both originate at the adjoint singularity at the trailing edge. The argument is extended to cover the fully compressible case, in subcritical flow conditions, by presenting an analytic solution that follows the same structure as the incompressible one.

Comparison of the Flow around Circular and Rectangular Emergent Cylinders with Subcritical and Supercritical Conditions

There are multiple initiatives aimed at strengthening coastal communities against tsunami disaster risks, such as growing vegetation belts, construction of embankments, moats, and different hybrid alternatives. To find a solution for strengthening the coastal buildings themselves, we firstly reviewed the flow phenomena around a single emergent (circular and rectangular) cylinder (case C1), which was considered as a piloti-type column under different Froude conditions, and evaluated the formation of surface bow-waves, hydraulic jump detachment, and wall-jet-like bow-waves. Secondly, the flow characteristics were investigated under the same Froude conditions with side-by-side two-cylinder (case C2) and four-cylinder (case C4) arrays in an open channel. Surface bow-wave length (LBw) increased by 7–12% over the rectangular cylinders (RCs) compared to the circular cylinders (CCs) with a subcritical flow. For the supercritical flow with a 1/200 bed slope, hydraulic jump detachment was observed in relation to the Froude number. The observed length of the hydraulic jump detachment (Ljump) varied between 3.1–8.5% and 4.2–12.9% for the CCs and RCs in the supercritical flow with a 1/200 bed slope. In addition, the wall-jet-like bow-wave height (hjet) over the CCs was increased by 37% and 29% compared to the RCs with a supercritical flow and zero bed slope (orifice-type flow). For case C4, a hydraulic jump was observed for the supercritical flow over the horizontal channel bed. Finally, empirical equations were defined concerning the geometrical shape and arrangement based on the experiment data for the single and side-by-side configurations of the cylinders to validate the height of the wall-jet-like bow-wave as the most critical flow property.

A comparison of lattice Boltzmann schemes for sub-critical shallow water flows

In this paper, we test the numerical properties of several variants of the lattice Boltzmann method (LBM) for simulating the shallow water flows. Specifically, we perform a systematic comparison of five different schemes: (i) the single-relaxation-time LBM, the (ii) raw-moments-based and (iii) central-moments-based multiple-relaxation-time LBMs, and the (iv) two-stages and (v) one-stage simplified LBMs. Concerning the latter, traditional simplified schemes require a fractional step two-stages technique. Building on the work Delgado-Gutiérrez et al. [“A single-step and simplified graphics processing unit lattice Boltzmann method for high turbulent flows,” Int. J. Numer. Methods Fluids 93, 2339–2361 (2021)], we derive a one-stage approach, where the procedure spans the grid points just once per time step. All the aforementioned LBMs are tested against five well-consolidated benchmark problems, and their numerical performance is assessed. Overall, populations-based schemes show superior accuracy and convergence properties. We link this behavior to the higher numerical dissipation introduced by the simplified models.

Discharge Coefficient of Symmetrical Stepped and Triangular Labyrinth Side Weirs in a Subcritical Flow Regime

The labyrinth side weir structure is an optimal solution to regulate and divert excess flows across rivers, and irrigation and drainage channels when the opening length of the side weir is limited. Changing the geometry of the side weir is considered one way to improve its efficiency. The present study investigates the hydraulic effects of stepped labyrinth side weirs to increase their discharge capacity. To estimate the outflow over symmetrical stepped labyrinth side weir, the discharge coefficient needs to be determined. Normal triangular labyrinth side weir in one cycle mode has been modified by increasing the crest path using different steps. A total of 417 experiments were conducted on normal and stepped side weirs for various weir opening lengths, weir heights, internal head angles, and hydraulic conditions. The results were analyzed and compared. It was found that efficiency improved, and the discharge coefficient increased as the number of the steps decreased. Furthermore, the water surface profile becomes more uniform with decreasing number of steps. A lower number of steps, smaller head angle, and high weir length produce a higher discharge coefficient by approximately 15%–35% compared to a normal triangular labyrinth side weir; in addition, the Knope length decreases by approximately 40%–70% for the same effective length. Additionally, a reliable equation to estimate the discharge coefficient of the stepped labyrinth side weir was presented. The results of this study can be used to design side weirs with high hydraulic performance when the weir-included angle selected is small or there is a lack of space.

Experimental Establishing of Moving Hydraulic Jump in a Trapezoidal Channel

This research was prepared as a preliminary laboratory study to achieve a moving hydraulic jump with controlled discharges. It is an initial part of the study that is being prepared to treat the salt tide occurring in the Shatt al-Arab due to the lack of water imports that were coming from the Karun and Karkheh rivers from Iranian territory, as this scarcity caused a salt tide that affected significantly the environmental reality of the city of Basra and the agricultural lands surrounding the Shatt al-Arab, such as the Shatt al-Arab district and the Siba orchards. As part of the proposed solutions, a moving hydraulic jump is created that pushes the salt tongue into the Persian Gulf; the results were promising. A moving hydraulic leap is a good example of unstable super- and sub-critical flow regimes and is regarded as a specific case of unsteady flow in a channel. There aren't many published experiments on this particular flow type, and the quantitative simulation of such a flow state has some inherent complexity. An experimental setup was created for this work in order to assess the hydraulic performance of a moving hydraulic jump in a trapezoidal flume. A sluice gate was installed at the flume's upstream edge to provide an unstable supercritical flow regime, movable hydraulic jumps along the channel, and temporal water stages at the gate's upstream side for the various downstream end boundary situations. Several flow factors, including energy head, pressure head, and flow depth, were estimated from the recorded data. The study found connections between discharge and shifting hydraulic jump variables. By employing relatively stable momentum and energy formulas, simple and time-independent formulas were developed that accurately predicted the pressure head in the subcritical region of an unstable mixed flow. As a result, the moving hydraulic jump factor can be correctly predicted using time-independent correlations by using the discharge variation as a boundary scenario. Doi: 10.28991/CEJ-2023-09-04-08 Full Text: PDF

Experimental investigation for the local scour around V-shaped spur-dikes

Spur-dikes are efficient hydraulic structures that are made for numerous purposes. They have one end on the stream bank and another extending into the current. As a result of the existing spur-dikes in the stream course, the local scour phenomena usually occur around them, leading to several predicaments which have been of great concern to the hydraulic engineers. For the present work, laboratory experiments were carried out to measure the scour depths around several spur-dikes located at different distances for the V-shaped one. The experiments were conducted using physical models installed in a non-curved flume with a bed with uniform cohesion-less sediment of a medium particle size (d50 = 0.7 mm). All the models were operated under the subcritical flow of clear-water conditions. The investigations include three spur-dikes (1, 2 and 3) and three distances between them (1, 1.5 and 2 of spur-dike length) as two countermeasures to minimize the local scour depths. The results showed that an increasing number of spur-dikes and the distances between them would decrease the scour depths within the limit of the present study. The experimental data were used to create a new formula of R2 = 0.954 that reflects a good agreement with the experimentally observed results.

Response of flow hydraulic parameters to different rock fragment coverages and sizes under simulated rainfall

Rock fragments widely occur on slopes and play a vital role in flow hydraulics, which in turn greatly affects soil erosion. This study aimed to explore the effects of the rock fragment coverage and size on flow hydraulic parameters and determine the optimal flow hydraulic predictor of soil loss rate. A series of simulated rainfall experiments (intensity: 60 mm h-1) were conducted in a 2 × 1 × 0.3 m flume with a gradient of 15°. The rock fragment treatments included a combination of eight sizes (0.7, 1.1, 3.0, 5.5, 12.0, 18.8, 26.4, 36.0 cm) and four coverages (15, 30, 45, 60%). Bare land was used as a control. The results indicated that compared with bare land, rock fragments remaining on the soil surface decreased the flow velocity (V) by 1–51% but increased the flow depth by 8–315%. Laminar flow occurred in all experiments (Reynolds number < 500). Only the overland flow under rock fragment sizes ≤ 3 cm was subcritical flow. Resistance (f) exponentially increased with rock fragment coverage at each size, while grain resistance percentage (f'/f) exponentially decreased with rock fragment coverage. Rock fragment size impacted positively on f’/f, grain shear stress (τ'), stream power (ω), grain stream power (ω'), but negatively on f. τ’ and ω’ decreased with rock fragment coverage in exponential equations, and the parameters in the equations logarithmically increased with rock fragment size. The soil loss rate increased exponentially with V and τ’, and increased linearly with ω’. ω’ was the optimal hydraulic parameter for soil loss prediction (R2 = 0.88; NSE = 0.80). Our findings can help to deepen the understanding of the mechanisms of the soil erosion process and provide insights into establishing soil loss prediction models on stony slopes.

Experimental research on aerosol scrubbing characteristics under steam-air mixture submerged jet condition

The occurrence of severe accidents in nuclear power plants may lead to the leakage of radioactive aerosol. And the scrubbing efficiency of aerosol contained in the air-steam mixture submerged jet is important for assessing the radioactivity in the containment during a severe accident. Several experiments were carried out to analyze the effect of inlet pressure, aerosol diameter, submergence, and steam fraction on the scrubbing efficiency of aerosol in the jet regime. Then, the scrubbing effects of steam and different flow regimes under submerged jet conditions were investigated by comparing the experimental results. The scrubbing efficiency increased with the increase of the aerosol diameter in the air jet regime while the most penetrating region of the aerosol in the steam-air mixture jet regime is 0.2–0.4 μm. When the gas flow characteristic is subcritical flow, as the inlet pressure increases, the scrubbing efficiency increases rapidly. When the critical flow is reached, the inertial effect was the dominant factor in aerosol scrubbing due to the sufficient gas velocity, the scrubbing efficiency under different steam fractions is close to 100%. The scrubbing efficiency increases with the increase of the steam fraction, which may be caused by the increase of the temperature gradient field under subcritical flow conditions. Additionally, the increase the submergence can increase the residence time and improve the scrubbing efficiency. However, due to the decrease of the gas velocity during the gas floating, the scrubbing efficiency in the flow region of the same height is gradually decreasing.