Simulated Cyclone Research Articles

Two Types of Transitions to Relatively Fast Spinup in Tropical Cyclone Simulations with Weak-to-Moderate Environmental Vertical Wind Shear

Abstract Tropical cyclone intensification is simulated with a cloud-resolving model under idealized conditions of constant SST and unidirectional environmental vertical wind shear maximized in the middle troposphere. The intensification process commonly involves a sharp transition to relatively fast spinup before the surface vortex achieves hurricane-force winds in the azimuthal mean. The vast majority of transitions fall into one of two categories labeled S and A. Type S transitions initiate quasi-symmetric modes of fast spinup. They occur in tropical cyclones after a major reduction of tilt and substantial azimuthal spreading of inner-core convection. The lead-up also entails gradual contractions of the radii of maximum wind speed rm and maximum precipitation. Type A transitions begin before an asymmetric tropical cyclone becomes vertically aligned. Instead of enabling the transition, alignment is an essential part of the initially asymmetric mode of fast spinup that follows. On average, type S transitions occur well after and type A transitions occur once the cyclonically rotating tilt vector becomes perpendicular to the shear vector. Prominent temporal peaks of lower-tropospheric CAPE and low-to-midlevel relative humidity averaged over the entire inner core of the low-level vortex characteristically coincide with type S but not with type A transitions. Prominent temporal peaks of precipitation and midlevel vertical mass flux in the meso-β-scale vicinity of the convergence center characteristically coincide with type A but not with type S transitions. Despite such differences, in both cases, the transitions tend not to begin before the distance between the low-level convergence and vortex centers divided by rm reduces to unity.

TC-SINDy: Improving physics-based deterministic tropical cyclone track and intensity model via data-driven sparse identification of Nonlinear Dynamics

Physics-based deterministic tropical cyclone (TC) simulation models play an important role in TC risk analysis, for their unique capability to represent physical principles and incorporate climate change impacts. However, establishing effective deterministic models can be challenging. In this paper, we present a simple yet powerful framework that distills physics-based TC models from historical TC data. By treating TC evolutions as dynamical systems, we adaptively discover the TC track and intensity governing equations from historical TC and environmental data via the Sparse Identification of Nonlinear Dynamics (SINDy) approach. Our proposed TC-SINDy approach is able to identify parsimonious, interpretable yet effective physics-based TC models. Compared to alternative physics-based deterministic models, our models match historical records much better in terms of the intensity evolution, prevailing tracks, and key parameter statistics across the coastlines of the Western North Pacific (WNP) basin and the North Atlantic (NA) basin. Our proposed models were finally coupled with a widely used parametric wind field, and the obtained probabilistic distribution of the surface wind also matched the historical histograms. Overall, the proposed method presents a general data-driven framework for discovering physics-based TC models, enabling reliable effective TC simulations while reserving the capacity to accommodate the changing climate.

Influence of convective parameterization on the simulation of tropical cyclones over the South West Indian Ocean: A case study of tropical cyclone Idai (2019)

Proper configuration of the physical parameterization scheme is important for accurate outcomes of mesoscale weather forecasting model. This study evaluates the performance of four distinct cumulus parameterization schemes: the Kain-Fritsch (KF), Grell 3D ensemble (GR3D), Modified Tiedtke (MTIEDKE) and Modified Kain-Fritsch (MKF) schemes, in simulating Tropical Cyclone (TC) Idai (2019) in the Southern Indian Ocean. Utilizing the Weather Research Forecasting (WRF) model and TC best-track and satellite precipitation datasets, the research assesses the models' efficacy in replicating Idai's observed track and intensity. Results indicate that the KF, MTIEDKE, and MKF schemes reasonably capture Idai's southwestward track, with MKF demonstrating superior accuracy in reproducing observed intensity evolution. Conversely, the GR3D simulation exhibits a northwestward deviation, leading to notable track and intensity errors. Further investigations suggest that the smaller track and intensity differences in the MKF simulation are linked to the more accurate simulation of rainfall in both the surrounding environment and the TC inner-core region. The two factors exert strong influences on the large-scale steering flow and TC secondary circulation, respectively. The findings underscore the importance of selecting appropriate convective parameterization schemes for precise tropical cyclone simulations in the Southern Indian Ocean. This research contributes valuable insights into the intricate interaction between convective processes and atmospheric dynamics, offering implications for enhancing tropical cyclone prediction models in the region.

Increasing coastal exposure to extreme wave events in the Alaskan Arctic as the open water season expands

Declining Arctic sea ice over recent decades has been linked to growth in coastal hazards affecting the Alaskan Arctic. In this study, climate model projections of sea ice are utilized in the simulation of an extratropical cyclone to quantify how future changes in seasonal ice coverage could affect coastal waves caused by this extreme event. All future scenarios and decades show an increase in coastal wave heights, demonstrating how an extended season of open water in the Chukchi and Beaufort Seas could expose Alaskan Arctic shorelines to wave hazards resulting from such a storm event for an additional winter month by 2050 and up to three additional months by 2070 depending on climate pathway. Additionally, for the Beaufort coastal region, future scenarios agree that a coastal wave saturation limit is reached during the sea ice minimum, where historically sea ice would provide a degree of protection throughout the year.

The upstream–downstream connection of North Atlantic and Mediterranean cyclones in semi-idealized simulations

Abstract. Cyclogenesis in the Mediterranean is typically triggered by the intrusion of a potential vorticity (PV) streamer over the Mediterranean. The intrusion of the PV streamer results from a preceding Rossby wave breaking (RWB) upstream over the North Atlantic. The ridge leading to the RWB is typically amplified by the presence of warm conveyor belts (WCBs) in at least one North Atlantic cyclone about 4 d prior to Mediterranean cyclogenesis. Thus, the sequence of these four main events (namely a North Atlantic cyclone, WCBs, RWB, and the resulting PV streamers) forms an archetypal scenario leading to Mediterranean cyclogenesis. However, they rarely occur in a spatially consistent, fully repetitive pattern for real cyclone cases. To more systematically study this connection between upstream North Atlantic cyclones and Mediterranean cyclogenesis, we perform a set of semi-idealized simulations over the Euro-Atlantic domain. For these simulations, we prescribe a constant climatological atmospheric state in the initial and boundary conditions. To trigger the downstream Mediterranean cyclogenesis scenario, we perturb the climatological polar jet through the inversion of a positive upper-level PV anomaly. The amplitude of this perturbation determines the intensity of the triggered North Atlantic cyclone. This cyclone provokes RWB, the intrusion of a PV streamer over the Mediterranean, and thereby the formation of a Mediterranean cyclone. Therefore, our results show a direct connection between the presence of a North Atlantic cyclone and the downstream intrusion of a PV streamer into the Mediterranean, which causes cyclogenesis about 4 d after perturbing the polar jet. We refer to this as the upstream–downstream connection of North Atlantic and Mediterranean cyclones. To investigate the sensitivity of this connection, we vary the position and amplitude of the upper-level PV anomaly. In all simulations, cyclogenesis occurs in the Mediterranean. Nevertheless, the tracks and intensity of the Mediterranean cyclones may vary by up to 20° and 10 hPa (at the time of the mature stage), respectively. This indicates that the Mediterranean cyclone dynamics are sensitive to the dynamical structure and amplitude of the intruding PV streamer, which itself is sensitive to the interaction of the upstream cyclone and the RW(B). By applying different seasonal climatological atmospheric states as initial conditions we show that cyclogenesis occurs in distinct regions in different seasons. Thus, the seasonal cycle of Mediterranean cyclogenesis might be partly determined by the large-scale atmospheric circulation, i.e., the seasonal location of the polar jet. Furthermore, we show that the Mediterranean cyclones in these semi-idealized simulations show characteristics that agree with the observed climatology of Mediterranean cyclones in the respective season.

Tropical cyclones in global high-resolution simulations using the IPSL model

Despite many years of extensive research, the evolution of Tropical Cyclone (TC) activity in our changing climate remains uncertain. This is partly because the answer to that question relies primarily on climate simulations with horizontal resolutions of a few tens of kilometers. Such simulations have only recently become accessible for most modeling centers, including the Institut Pierre-Simon Laplace (IPSL). Using recent numerical developments in the IPSL model, we perform a series of historical atmospheric-only simulations that follow the HighResMIP protocol. We assess the impact of increasing the resolution from ∼200\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\sim }\\, 200$$\\end{document} to 25 km on TC activity. In agreement with previous work, we find a systematic improvement of TC activity with increasing resolution with respect to the observations. However, a clear signature of TC frequencies convergence with resolution is still lacking. Cyclogenesis geographical distributions also improve at the scale of individual basins. This is particularly true of the North Atlantic, where the agreement with the observed distribution is impressive at 25 km. In agreement with the observations, TC activity correlates with the large-scale environment and ENSO in that basin. By contrast, TC frequencies remain too small in the Western North Pacific at 25 km, where significant biases of humidity and vorticity are found compared to the reanalysis. Despite the few minor weaknesses we identified, our results demonstrate that the IPSL model is a suitable tool for studying TCs on climate time scales. This work thus opens the way for further studies contributing to our understanding of TC climatology.

Modeling Variability in Tropical Cyclone Maximum Wind Location and Intensity Using InCyc: A Global Database of High-Resolution Tropical Cyclone Simulations

Abstract While tropical cyclone (TC) risk is a global concern, high regional differences exist in the quality of available data. This paper introduces InCyc, a globally consistent database of high-resolution full-physics simulations of historical cyclones. InCyc is designed to facilitate analysis of TC wind risk across basins and is made available to research institutions. We illustrate the value of this database with a case study focused on key wind risk parameters, namely, the location and intensity of peak winds for the North Atlantic and western North Pacific basins. A novel approach based on random forest algorithms is introduced to predict the full distribution of these TC wind risk parameters. Based on a leave-one-storm-out evaluation, the analysis of the predictions shows how this innovative approach compares to other parametric models commonly used for wind risk assessment. We finally discuss why capturing the full distribution of variability is crucial as well as the broader use in the context of TC risk assessment systems (i.e., “catastrophe models”).

Parameterizations of Boundary Layer Mass Fluxes in High-Wind Conditions for Tropical Cyclone Simulations

Abstract Development of accurate planetary boundary layer (PBL) parameterizations in high-wind conditions is crucial for improving tropical cyclone (TC) forecasts. Given that eddy-diffusivity mass-flux (EDMF)-type PBL schemes are designed for nonhurricane boundary layers, this study examines the uncertainty of MF parameterizations in hurricane conditions by performing three-dimensional idealized simulations. Results show that the surface-driven MF plays a dominant role in the nonlocal turbulent fluxes and is comparable to the magnitude of downgradient momentum fluxes in the middle portion of TC boundary layers outside the radius of maximum wind (RMW); in contrast, the stratocumulus-top-driven MF is comparably negligible and exerts a marginal impact on TC simulations. To represent the impact of vertical wind shear on damping rising thermal plumes, a new approach of tapering surface-driven MF based on the surface stability parameter is proposed, aiming to retain the surface-driven MF only in unstable boundary layers. Compared to a traditional approach of MF tapering based on 10-m wind speeds, the new approach is physically more appealing as both shear and buoyancy forcings are considered and the width of the effective zone responds to diurnal variations of surface buoyancy forcing. Compared to the experiments retaining the original MF components, using either approach of MF tapering can lead to a stronger and more compact inner core due to enhanced boundary layer inflow outside the RMW; nevertheless, the radius of gale-force wind and inflow layer depth are only notably reduced using the new approach. Comparison to observations and further discussions on MF parameterizations in high-wind conditions are provided.

The Two- to Four-Day Predictability of Midlatitude Cyclones: Don’t Sweat the Small Stuff

Abstract We use convection-permitting idealized simulations of moist midlatitude cyclones to compare the growth of synoptic-scale perturbations derived from an adjoint model with the growth of equal-energy-norm, monochromatic-wavelength perturbations at the smallest resolved scale. For initial magnitudes comparable to those of initial-condition uncertainties in present-day data assimilation systems, the adjoint perturbations produce a “forecast bust,” significantly changing the intensity and location of the cyclone and its accompanying precipitation. In contrast, the small-scale-wave perturbations project strongly onto the moist convection, but the upscale growth from the random displacement of individual convective cells does not significantly alter the cyclone’s development nor its accompanying precipitation through 2–4-day lead times. Instead, the differences in convection generated at early times become negligible because the development of subsequent convection is driven by the mostly unchanged synoptic-scale flow. Reducing the perturbation magnitudes by factors of 10 and 100 demonstrates that nonlinear dynamics play an important role in the displacement of the cyclone by the full-magnitude adjoint perturbations, and that the upscale growth of small-magnitude, small-scale perturbations is too slow to significantly change the cyclone. These results suggest that a sensitive dependence on the synoptic-scale initial conditions, analogous to that of the Lorenz (1963) system, may be more relevant to 2–4-day midlatitude-cyclone forecast busts than the upscale error growth in the Lorenz (1969) model.

Moisture control of tropical cyclones in high-resolution simulations of paleoclimate and future climate

The intensity of tropical cyclones (TCs) is expected to increase in response to greenhouse warming. However, how future climate change will affect TC frequencies and tracks is still under debate. Here, to further elucidate the underlying sensitivities and mechanisms, we study TCs response to different past and future climate forcings. Using a high-resolution TC-resolving global Earth system model with 1/4° atmosphere and 1/10° ocean resolution, we conducted a series of paleo-time-slice and future greenhouse warming simulations targeting the last interglacial (Marine Isotope Stage (MIS) 5e, 125 ka), glacial sub-stage MIS5d (115 ka), present-day (PD), and CO2 doubling (2×CO2) conditions. Our analysis reveals that precessional forcing created an interhemispheric difference in simulated TC densities, whereas future CO2 forcing impacts both hemispheres in the same direction. In both cases, we find that TC genesis frequency, density, and intensity are primarily controlled by changes in tropospheric thermal and moisture structure, exhibiting a clear reduction in TC genesis density in warmer hemispheres.

Large-Scale Circulations and Dry Tropical Cyclones in Direct Numerical Simulations of Rotating Rayleigh–Bénard Convection

Abstract The organization of convection into relatively long-lived patterns of large spatial scales, like tropical cyclones, is a common feature of Earth’s atmosphere. However, many key aspects of convective aggregation and its relationship with tropical cyclone formation remain elusive. In this work, we simulate highly idealized setups of dry convection, inspired by the Rayleigh–Bénard system, to probe the effects of different thermal boundary conditions on the scale of organization of rotating convection, and on the formation of tropical cyclone–like structures. We find that in domains with sufficiently high aspect ratios, moderately turbulent (), moderately rotating () convection organizes more persistently and at larger scales when thermal boundary conditions constrain heat fluxes rather than temperatures. Furthermore, for some thermal boundary conditions with asymmetric heat fluxes, convection organizes into persistent vortices with the essential properties of mature tropical cyclones: a warm core, high axisymmetry, a strong azimuthal circulation, and substantially larger size than individual buoyant plumes. We argue that flux asymmetry results in a persistent and localized input of buoyancy, which allows spatially aggregated convection to sustain a warm core in a developing large-scale vortex. Crucially, the most intense and axisymmetric cyclone forms for setups where the bottom heat flux is enhanced by the nearby flow and the top boundary is insulating, as long as the convective Rossby number is higher than about 1. Our results demonstrate the great potential for dialogue between classical turbulence research and the study of convective aggregation and tropical cyclones. Significance Statement On Earth, atmospheric convection frequently organizes into large spatial patterns that persist for several days, like tropical cyclones. However, many aspects of this process of organization and its link to tropical cyclone formation are not fully understood. In this work, we use numerical simulations of simple setups of rotating convection without moisture to study the minimal conditions that produce large-scale convective organization, and the spontaneous formation of tropical cyclone–like structures. We find that the latter form more readily for a particular set of controlling parameters and thermal boundary conditions. Our approach seeks to narrow the disciplinary gap between tropical cyclone physics and traditional turbulence research, by bringing together methods, questions, and results that are of potential interest to both.

Characterization of the 2012 and 2013 Metro Manila “Enhanced Habagat” Heavy Rainfall Events

The strong southwest monsoon episodes in August 2012 and 2013, locally referred to as the “Enhanced Habagat ” 2012 and 2013, respectively, resulted in rainfall that exceeded the monthly mean rainfall of the affected regions along western Luzon, including Metro Manila. The prolonged heavy rainfall events were the result of tropical cyclone enhancement of the monsoon winds. The synoptic environment in the two events was characterized by the deepening of the Asian monsoon trough depicted by the zonally-oriented and eastward-extended 1000 hPa isobar. The deep troughs were caused each year by a combination of tropical cyclones located to the northeast of the Philippines – Typhoon Haikui in 2012 and Severe Tropical Storm Trami in 2013, and remnant tropical cyclones in the northern South China Sea region that formed several days prior to the enhanced Habagat episodes. The monsoon trough induced a low-level westerly jet in the South China Sea toward the western Luzon region that transported a narrow stream of moisture-laden air mass to Metro Manila and surrounding areas. Consequently, heavy precipitation ensued. Analysis showed the remnant lows are as important as the enhancing tropical cyclones Haikui and Trami in inducing the westerly jets. Removal of the enhancing tropical cyclones in numerical model simulations still showed a relatively deep monsoon trough that led to heavy rainfall along western Luzon. In addition, the intrusion of low potential vorticity area to the eastern and northern flanks of the tropical cyclones facilitated the strengthening of the steering ridge that resulted in their westward and slow translational motion, making the events last for several days and exacerbating the impacts. Furthermore, the Madden-Julian Oscillation possibly serves as a precursor to heavy rainfall events. Compounded with a populous megacity, understanding the mechanisms that lead to these extreme hazards is vital to future forecasting and disaster risk management of similar events.

The Effect of Advection on the Three Dimensional Distribution of Turbulent Kinetic Energy and Its Generation in Idealized Tropical Cyclone Simulations

AbstractThe distribution of turbulent kinetic energy (TKE) and its budget terms is estimated in simulated tropical cyclones (TCs) of various intensities. Each simulated TC is subject to storm motion, wind shear, and oceanic coupling. Different storm intensities are achieved through different ocean profiles in the model initialization. For each oceanic profile, the atmospheric simulations are performed with and without TKE advection. In all simulations, the TKE is maximized at low levels (i.e., below 1 km) and ∼0.5 km radially inward of the azimuthal‐mean radius of maximum wind speed at 1‐km height. As in a previous study, the axisymmetric TKE decreases with height in the eyewall, but more abruptly in simulations without TKE advection. The largest TKE budget terms are shear generation and dissipation, though variability in vertical turbulent transport and buoyancy production affect the change in the azimuthal‐mean TKE distribution. The general relationships between the TKE budget terms are consistent across different radii, regardless of storm intensity. In terms of the asymmetric distribution in the eyewall, TKE is maximized in the front‐left quadrant where the sea surface temperature (SST) is highest and is minimized in the rear‐right quadrant where the SST is the lowest. In the category‐5 simulation, the height of the TKE maximum varies significantly in the eyewall between quadrants and is between ∼400 m in the rear‐right quadrant and ∼1,000 m in the front‐left quadrant. When TKE advection is included in the simulations, the maximum eyewall TKE values are downwind compared to the simulations without TKE advection.

Modifications to Three‐Dimensional Turbulence Parameterization for Tropical Cyclone Simulation at Convection‐Permitting Resolution

AbstractAdequate representation of the subgrid‐scale (SGS) turbulent fluxes associated with convective clouds in the eyewall and rainbands above the boundary layer is important for simulating the formation of tropical cyclone (TC) dynamic and thermal structure, as well as the evolution and intensification of the TC. Two sets of benchmark large‐eddy simulations (LESs) for an idealized TC during the rapid intensification and mature stages were conducted. The turbulent transport above the boundary layer in the TC eyewall and rainbands exhibits a remarkable countergradient characteristic, which is poorly represented by the traditional eddy‐diffusivity closure. In contrast, the H‐gradient closure based on the horizontal gradients of the resolved variables is capable of accurately capturing the countergradient features and exhibiting a spatial distribution of SGS fluxes that mimics much better the coarse‐grained fluxes from the LES benchmarks. Moreover, the H‐gradient closure allows for the backscatter transfer of energy. By implementing the H‐gradient closure into a three‐dimensional turbulence parameterization, the TC simulated using the modified parameterization bears closer resemblance to the LES benchmarks in terms of the spatial distribution of SGS fluxes, TC intensity, primary and secondary circulations, and cloud morphology.

Regional climate simulation of tropical cyclone at gray-zone resolution over western North Pacific: with/without cumulus parameterization

Regional climate simulation of tropical cyclone at gray-zone resolution over western North Pacific: with/without cumulus parameterization

A One-Step-Ahead Ensemble Kalman Smoothing Approach Toward Estimating the Tropical Cyclone Surface-Exchange Coefficients

Abstract In this study, a one-step-ahead ensemble Kalman smoother (EnKS) is introduced for the purposes of parameter estimation. The potential for this system to provide new constraints on the surface-exchange coefficients of momentum (Cd) and enthalpy (Ck) is then explored using a series of observing system simulation experiments (OSSEs). The surface-exchange coefficients to be estimated within the data assimilation system are highly uncertain, especially at high wind speeds, and are well known to be important model parameters influencing the intensity and structure of tropical cyclones in numerical simulations. One major benefit of the developed one-step-ahead EnKS is that it allows for simultaneous updates of the rapidly evolving model state variables found in tropical cyclones using a short assimilation window and a long smoother window for the parameter updates, granting sufficient time for sensitivity to the parameters to develop. Overall, OSSEs demonstrate potential for this approach to accurately constrain parameters controlling the amplitudes of Cd and Ck, but the degree of success in recovering the truth model parameters varies throughout the tropical cyclone life cycle. During the rapid intensification phase, rapidly growing errors in the model state project onto the parameter updates and result in an overcorrection of the parameters. After the rapid intensification phase, however, the parameters are correctly adjusted back toward the truth values. Last, the relative success of parameter estimation in recovering the truth model parameter values also has sensitivity to the ensemble size and smoothing forecast length, each of which are explored. Significance Statement Large uncertainty in the surface-exchange coefficients of momentum and heat/moisture exists for hurricane conditions. This is a problem because the numerical weather model predictions of hurricane intensity and storm structure are sensitive to the surface-exchange coefficient values used. In this study we use data assimilation, or the relationships estimated between the surface-exchange coefficients and forecasted observations, to constrain uncertainty in the model’s surface-exchange coefficient values. More specifically, an approach to limit both the rapidly growing errors associated with the hurricane itself and the hurricane’s accumulated response to the surface-exchange coefficient values is presented. Overall, this approach has potential to accurately estimate the surface-exchange coefficients, but the success depends on the number of forecast realizations used and how rapidly the hurricane is changing.

Using virtual simulations of future extreme weather events to communicate climate change risk

Virtual simulations of future extreme weather events may prove an effective vehicle for climate change risk communication. To test this, we created a 3D virtual simulation of a future tropical cyclone amplified by climate change. Using an experimental framework, we isolated the effect of our simulation on risk perceptions and individual mitigation behaviour for a representative sample (n = 1507) of the general public in Hong Kong. We find that exposure to our simulation is systematically associated with a relatively small decrease in risk perceptions and individual mitigation behaviour. We suggest that this is likely due to climate change scepticism, motivation crowding, geographical and temporal distance, high-risk thresholds, feelings of hopelessness, and concerns surrounding the immersiveness of the virtual simulation.

Deep Learning Parameterization of the Tropical Cyclone Boundary Layer

AbstractThe research on tropical cyclone (TC) relieson numerical models and simulations, with the currently widely used boundary layer parameterization posing a significant challenge on accurately predicting turbulent mixing. However, machine learning has opened up new possibilities for boundary layer sub‐grid process parameterization. In this study, a deep‐learning parameterization scheme for the TC boundary layer (DeepBL) on predicting turbulent flux is proposed. DeepBL comprises a one‐dimensional convolutional structure that relies on a small number of learnable parameters that accomplishes an error reduction compared to the standard fully connected neural networks. Furthermore, a nonlinear transformation scheme is introduced to alleviate the training data's skewness and improve the DeepBL performance by affording a smaller prediction error. Specifically, the output data of a large‐eddy simulation of an idealized TC are used to train, validate, and test DeepBL, affording significantly better performance than the YSU scheme in the Weather Research and Forecast model. Interpretability analysis on DeepBL demonstrates that the deep‐learning parameterization scheme is physically reasonable.

Assessment of the impact of ocean mean temperature on numerical simulations of tropical cyclones

Assessment of the impact of ocean mean temperature on numerical simulations of tropical cyclones

Numerical simulation and experimental study of gas cyclone–liquid jet separator for fine particle separation

To address the shortcomings of existing particulate matter trapping technology, especially the low separation efficiency of fine particles, herein, a novel gas cyclone–liquid jet separator was developed to research fine particle trapping. First, numerical simulation methods were used to investigate the flow field characteristics and dust removal efficiency of the separator under different working conditions, and to determined suitable experimental conditions for subsequent dust removal experiments. Afterward, the separation efficiency of the separator against five kinds of common particles, including g-C 3 N 4 , TiO 2 , SiC, talc, and SiO 2 , was experimentally studied. A maximum separation efficiency of 99.48% was achieved for particles larger than 13.1 μm, and 96.55% efficiency was achieved for particles larger than 2 μm. The best crushing atomization effect was achieved for the separator when u G was 10 m·s −1 and u L was 3 m·s −1 , while the best separation effect was achieved when u G was 10 m·s −1 and u L was 3.75 m·s −1 . Studies have shown that the gas cyclone–liquid jet separator has excellent applicability in the separation of fine particles.