[ Objective] The research aimed to study application of the trajectory plume model in atmospheric environmental impact assessment. [ Method] Trajectory plume model was used to retrospectively evaluate regional atmosph...[ Objective] The research aimed to study application of the trajectory plume model in atmospheric environmental impact assessment. [ Method] Trajectory plume model was used to retrospectively evaluate regional atmospheric improvement degree by fuel gas desulfurization project in Mawan Power Plant of Shenzhen. On this basis, we analyzed applicability of the model in atmospheric prediction of the construction project. [- Re- sult~ Under the situation of complex flow field and variable weather condition, the trajectory plume model displayed good prediction accuracy, to- gether with the use of flow field diagnosis model. Under complex weather condition, this model could be complementary to atmospheric environmen- tal quality prediction model recommended by new atmosphere guidelines, which had the value of popularization in future atmospheric environmental evaluation and planning. [ Conduslon~ Trajectory plume model had broad application potential in atmospheric environmental impact assessment.展开更多
Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental...Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental impact assessment of the proposed dredging, particularly those associated with suspended sediments and sedimentation. Model validation and performance are still not resolved because of the difficulty of site measurements and the understanding of the parameters used in the model. This paper presents a 3-D dredging plume model based on the MIKE3 software package to investigate parameters which affect the model performances. As a result of lack of site data for the public domain uses, the model scenarios are designed artificially for sensitive runs to identify the key parameters affecting plume behaviours. The factors include dredging spill rates using different dredging methods, equipment and sediment settling velocities. The influence of wave and wind effects combined with tidal forces on the sediment re-suspended rates and the advection/dispersion scales are also assessed.展开更多
The main objective of this paper is to estimate the plume dispersion parameters in lateral direction (σy) and vertical direction (σz) by using power law wind speed and the scheme of eddy diffusivity in unstable cond...The main objective of this paper is to estimate the plume dispersion parameters in lateral direction (σy) and vertical direction (σz) by using power law wind speed and the scheme of eddy diffusivity in unstable condition. Comparison among our model and algebraic [1] and integral [2] formulations were held. We find that our model and two other models are in agreement with observed data.展开更多
Currently, the mathematical code Modflow is widely used to simulate groundwater flow in aquifers. Due to the ease which exists today to create mathematical models through Modflow visual Interfaces, it is possible to o...Currently, the mathematical code Modflow is widely used to simulate groundwater flow in aquifers. Due to the ease which exists today to create mathematical models through Modflow visual Interfaces, it is possible to obtain contamiant transport results which may not have much support, especially when simulating the transport of contaminants with little groundwater flow information. Domenico’s equation is an analytical solution for transport of contaminants in groundwater that can be used when not much groundwater flow information exists. The objective of this study is to model, using Domenico’s equation, a groundwater contaminant plume that discharges into a tidally influenced river. The study area was a wood treatment facility located on the bank of a river which is influenced by tides. Previous studies have found the presence of creosote in the subsurface and the formation of a groundwater plume that apparently discharges into the river. Domenico’s equation was selected to model this site because of the limited piezometric data available at the site to properly simulate the daily hydraulic gradient inversion due to the river tides. Domenico’s equation was successfully used to model this plume and reproduce the field distribution of naphthalene, benzene and 1-methyl-naphthalene. Two sources 40 minland had to be defined to properly simulate the plume behavior. It was determined through modeling that biodegradation plays an important role on the plume’s behavior. These were key issues in the conceptual model understanding of the plume at this site.展开更多
This study seeks to determine the similarities in plume radiation between reduced and full-scale solid rocket models in ground test conditions through investigation of flow and radiation for a series of scale ratios r...This study seeks to determine the similarities in plume radiation between reduced and full-scale solid rocket models in ground test conditions through investigation of flow and radiation for a series of scale ratios ranging from 0.1 to 1. The radiative transfer equation (RTE) considering gas and particle radiation in a non-uniform plume has been adopted and solved by the finite volume method (FVM) to compute the three dimensional, spectral and directional radiation of a plume in the infrared waveband 2-6 mu m. Conditions at wavelengths 2.7 mu m and 4.3 mu m are discussed in detail, and ratios of plume radiation for reduced-scale through full-scale models are examined. This work shows that, with increasing scale ratio of a computed rocket motor, area of the high-temperature core increases as a 2 power function of the scale ratio, and the radiation intensity of the plume increases with 2-2.5 power of the scale ratio. The infrared radiation of plume gases shows a strong spectral dependency, while that of Al2O3 particles shows spectral continuity of gray media. Spectral radiation intensity of a computed solid rocket plume's high temperature core increases significantly in peak radiation spectra of plume gases CO and CO2 center dot Al2O3 particles are the major radiation component in a rocket plume. There is good similarity between contours of plume spectral radiance from different scale models of computed rockets, and there are two peak spectra of radiation intensity at wavebands 2.7-3.0 lm and 4.2-4.6 lm. Directed radiation intensity of the entire plume volume will rise with increasing elevation angle. (C) 2016 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd.展开更多
One of the most important characteristic signatures of the exhaust plume from rocket motor is the aflerbuming phenomenon, and the injected water into the plume could inhibit the afterburning. The calculation model for...One of the most important characteristic signatures of the exhaust plume from rocket motor is the aflerbuming phenomenon, and the injected water into the plume could inhibit the afterburning. The calculation model for the gas-liquid multiphase flow field with chemical reaction in the plume is built. By inducing the energy source terms caused by the vaporization of liquid water, condensation of the vapor and chemical reaction in the energy equation, the gas-liquid multiphase flow field and the afterburning phenomenon are calculated in a coupling way. Mixture multiphase flow model is used to calculate the gas-liquid flow field, and the vaporization mechanism is used to investigate the water vaporization process. The temperature contours are obtained and accord well with the experimental photos. The mass fraction contours of primary species are obtained, which can indicate the extent of inhibition effect of water injection on the afterburning phenomenon in the plume. When water is injected into the plume, the region of aflerburning reduces a lot, and temperature on the ground wall declines rapidly, which can decrease the ablation of the combustion gas to the launch ground.展开更多
The turbulent flow of vertical plane wall plume with concentration variation was studied with the finite analytical method. The k-epsilon model with the effect of buoyancy on turbulent kinetic energy and its dissipati...The turbulent flow of vertical plane wall plume with concentration variation was studied with the finite analytical method. The k-epsilon model with the effect of buoyancy on turbulent kinetic energy and its dissipation rate was adopted. There were similarity solutions in the uniform environment for the system of equations including the equation of continuity, the equation of momentum along the flow direction and concentration, and equations of k, epsilon. The finite analytic method was applied to obtain the similarity solution. The calculated data of velocity, relative density difference, the kinetic energy of turbulence and its dissipation rate distribution for vertical plane plumes are in good agreement with the experimental data at the turbulent Schmidt number equal to 1.0. The variations of their maximum value along the direction of main flow were also given. It shows that the present model is good, i.e., the effect of buoyancy on turbulent kinetic energy and its dissipation rate should be taken into account, and the finite analytic method is effective.展开更多
Marius Hills is a volcanic plateau on the nearside of the Moon. It is of great interest for its high concentration of volcanic features, including domes, cones, ridges, and rilles. However, the morphological and chron...Marius Hills is a volcanic plateau on the nearside of the Moon. It is of great interest for its high concentration of volcanic features, including domes, cones, ridges, and rilles. However, the morphological and chronological characteristics of this plateau were not well studied due to the low resolution of early mission data. This study describes the detailed morphology of the volcanic features using the latest high spatial resolution images of the Terrain Camera （TC） onboard Selene-1 （10 m/pix） and Narrow Angle Camera （NAC） onboard the Lunar Reconnaissance Orbiter （LRO） （0.5 m/pix）. We report here some new structures such as skylights and remnants of lava tubes. We have divided spectrally homogenous areas with Clementine UVVIS data and did crater size frequency distribution （CSFD） measurements with Lunar Orbiter （LO） IV and TC images in every spectral unit. We first report absolute model ages of 1.10 Ga for Marius basalt 1, 1.49 Ga for Fiamsteed basalt, and 1.46 Ga for Schiaparelli Basalt. In addition, we have identified several younger lava events： they are Marius basalt 2 （814 Ma）, medium to low titanium basalt （949 Ma）, and undifferentiated medium titanium basalt （687 Ma）. Finally, we propose a mantle plume scenario for the formation of Marius Hills, which could solve the inconsistency of previous models.展开更多
The conventional atmospheric dispersion models used in China (CRADM), America (HPDM) and Canada (AMS) are investigated. The main differences between the three models are described, and the various aspects of CRADM, HP...The conventional atmospheric dispersion models used in China (CRADM), America (HPDM) and Canada (AMS) are investigated. The main differences between the three models are described, and the various aspects of CRADM, HPDM and AMS for same input are compared and discussed. Some problems in application of atmospheric dispersion models to environmental impact assessment are analyzed and suggestions for rivision are proposed. Results show that the Briggs plume rise formula in neutral condition overestimates the real rise due to the fact that the accumulative effect of ambient turbulence on plume is not considered in his model.展开更多
A three-dimensional numerical model of the coastal plume in an ideal basin for the western Gulf of Maine of USA, based on the observations, was configured to examine the dynamical properties under the spring riverine,...A three-dimensional numerical model of the coastal plume in an ideal basin for the western Gulf of Maine of USA, based on the observations, was configured to examine the dynamical properties under the spring riverine, tidal, and wind forcing. The purpose of this paper is to reveal possible effects of different factors on the coastal plume. The control run with a sloping bottom mimicking the western Gulf of Maine reproduced a southward advection speed of 14 km/d, consistent with the observed speed of 13.3 km/d. The plume evolutions due to the two typical wind forcing, upwelling favourable (wind from north) and downwelling favourable (wind from south). were simulated to explain the observations during the spring of 1993. A systematic sensitivity study was also conducted on the following themes: model parameters. dynamic processes, and topography effect.展开更多
The East African Rift system （EARS） provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides o...The East African Rift system （EARS） provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides of the old thick Tanzanian craton embedded in a younger lithosphere. Data on the pre-rifr, syn-rift and post-rift far-field volcanic and tectonic activity show that the EARS formed in the context of the interaction between a deep mantle plume and a horizontally and vertically heterogeneous lithosphere under far-field tectonic extension. We bring quantitative insights into this evolution by implementing high-resolution 3D thermo-mechanical numerical deformation models of a lithosphere of realistic rheology. The models focus on the central part of the EARS. We explore scenarios of plumelithosphere interaction with plumes of various size and initial position rising beneath a tectonically pre-stretched lithosphere. We test the impact of the inherited rheological discontinuities （suture zones） along the craton borders, of the rheological structure, of lithosphere plate thickness variations, and of physical and mechanical contrasts between the craton and the embedding lithosphere. Our experiments indicate that the ascending plume material is deflected by the cratonic keel and preferentially channeled along one of its sides, leading to the formation of a large rift zone along the eastern side of the craton, with significant magmatic activity and substantial melt amount derived from the mantle plume material. We show that the observed asymmetry of the central EARS, with coeval amagmatic （western） and magmatic （eastern） branches, can be explained by the splitting of warm material rising from a broad plume head whose initial position is slightly shifted to the eastern side of the craton. In that case, neither a mechanical weakness of the contact between the craton and the embedding lithosphere nor the presence of second plume are required to produce simulations that match observations. This result reconciles the passive and active rift models and demonstrates the possibility of development of both magmatic and amagmatic rifts in identical geotectonic environments.展开更多
The plume interaction above an alternating diffuser in stagnant water is studied with 3D Reynolds-averaged NavierStokes equations （RANS） combined with a buoyancy-extended κ-ε model. The steady three-dimensional tu...The plume interaction above an alternating diffuser in stagnant water is studied with 3D Reynolds-averaged NavierStokes equations （RANS） combined with a buoyancy-extended κ-ε model. The steady three-dimensional turbulent flow and temperature fields are computed by use of the finite volume method on a non-uniform high resolution orthogonal grid. The numerical predictions demonstrate a generic flow pattern for different turbulent heated jet discharges： the buoyant jets on each side of the diffuser first merge to form an essentially two-dimensional plume which bends back toward the diffuser centerline due to a low pressure cavity. In general, an under-pressure exists in the cavity until the plumes merge; the pressure increases to slightly positive afterwards. Two-dimensionality of the scalar and flow field is attained much later than the point of zero pressure. The position of merging point is governed by mainly four parameters - the discharge densimetfic Froude number, the port diameter and space, and the horizontal distance between alternating jet nozzles. A formula from numerical simulations is obtained through regression analysis and it is used to predict the position of plume merging point. The predicted temperature fields are comparable to previous experiments.展开更多
文摘[ Objective] The research aimed to study application of the trajectory plume model in atmospheric environmental impact assessment. [ Method] Trajectory plume model was used to retrospectively evaluate regional atmospheric improvement degree by fuel gas desulfurization project in Mawan Power Plant of Shenzhen. On this basis, we analyzed applicability of the model in atmospheric prediction of the construction project. [- Re- sult~ Under the situation of complex flow field and variable weather condition, the trajectory plume model displayed good prediction accuracy, to- gether with the use of flow field diagnosis model. Under complex weather condition, this model could be complementary to atmospheric environmen- tal quality prediction model recommended by new atmosphere guidelines, which had the value of popularization in future atmospheric environmental evaluation and planning. [ Conduslon~ Trajectory plume model had broad application potential in atmospheric environmental impact assessment.
文摘Dredging plume dispersion studies, use dredging plume models to predict the fate of sediment plumes resulting from dredging activities and dredge spoil disposal. The model results are applied as input to environmental impact assessment of the proposed dredging, particularly those associated with suspended sediments and sedimentation. Model validation and performance are still not resolved because of the difficulty of site measurements and the understanding of the parameters used in the model. This paper presents a 3-D dredging plume model based on the MIKE3 software package to investigate parameters which affect the model performances. As a result of lack of site data for the public domain uses, the model scenarios are designed artificially for sensitive runs to identify the key parameters affecting plume behaviours. The factors include dredging spill rates using different dredging methods, equipment and sediment settling velocities. The influence of wave and wind effects combined with tidal forces on the sediment re-suspended rates and the advection/dispersion scales are also assessed.
文摘The main objective of this paper is to estimate the plume dispersion parameters in lateral direction (σy) and vertical direction (σz) by using power law wind speed and the scheme of eddy diffusivity in unstable condition. Comparison among our model and algebraic [1] and integral [2] formulations were held. We find that our model and two other models are in agreement with observed data.
文摘Currently, the mathematical code Modflow is widely used to simulate groundwater flow in aquifers. Due to the ease which exists today to create mathematical models through Modflow visual Interfaces, it is possible to obtain contamiant transport results which may not have much support, especially when simulating the transport of contaminants with little groundwater flow information. Domenico’s equation is an analytical solution for transport of contaminants in groundwater that can be used when not much groundwater flow information exists. The objective of this study is to model, using Domenico’s equation, a groundwater contaminant plume that discharges into a tidally influenced river. The study area was a wood treatment facility located on the bank of a river which is influenced by tides. Previous studies have found the presence of creosote in the subsurface and the formation of a groundwater plume that apparently discharges into the river. Domenico’s equation was selected to model this site because of the limited piezometric data available at the site to properly simulate the daily hydraulic gradient inversion due to the river tides. Domenico’s equation was successfully used to model this plume and reproduce the field distribution of naphthalene, benzene and 1-methyl-naphthalene. Two sources 40 minland had to be defined to properly simulate the plume behavior. It was determined through modeling that biodegradation plays an important role on the plume’s behavior. These were key issues in the conceptual model understanding of the plume at this site.
基金co-supported by the National Natural Science Foundation of China (Nos. 51376065 and 51176052)Guangdong Key Scientific Project (No. 2013B010405004)
文摘This study seeks to determine the similarities in plume radiation between reduced and full-scale solid rocket models in ground test conditions through investigation of flow and radiation for a series of scale ratios ranging from 0.1 to 1. The radiative transfer equation (RTE) considering gas and particle radiation in a non-uniform plume has been adopted and solved by the finite volume method (FVM) to compute the three dimensional, spectral and directional radiation of a plume in the infrared waveband 2-6 mu m. Conditions at wavelengths 2.7 mu m and 4.3 mu m are discussed in detail, and ratios of plume radiation for reduced-scale through full-scale models are examined. This work shows that, with increasing scale ratio of a computed rocket motor, area of the high-temperature core increases as a 2 power function of the scale ratio, and the radiation intensity of the plume increases with 2-2.5 power of the scale ratio. The infrared radiation of plume gases shows a strong spectral dependency, while that of Al2O3 particles shows spectral continuity of gray media. Spectral radiation intensity of a computed solid rocket plume's high temperature core increases significantly in peak radiation spectra of plume gases CO and CO2 center dot Al2O3 particles are the major radiation component in a rocket plume. There is good similarity between contours of plume spectral radiance from different scale models of computed rockets, and there are two peak spectra of radiation intensity at wavebands 2.7-3.0 lm and 4.2-4.6 lm. Directed radiation intensity of the entire plume volume will rise with increasing elevation angle. (C) 2016 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd.
文摘One of the most important characteristic signatures of the exhaust plume from rocket motor is the aflerbuming phenomenon, and the injected water into the plume could inhibit the afterburning. The calculation model for the gas-liquid multiphase flow field with chemical reaction in the plume is built. By inducing the energy source terms caused by the vaporization of liquid water, condensation of the vapor and chemical reaction in the energy equation, the gas-liquid multiphase flow field and the afterburning phenomenon are calculated in a coupling way. Mixture multiphase flow model is used to calculate the gas-liquid flow field, and the vaporization mechanism is used to investigate the water vaporization process. The temperature contours are obtained and accord well with the experimental photos. The mass fraction contours of primary species are obtained, which can indicate the extent of inhibition effect of water injection on the afterburning phenomenon in the plume. When water is injected into the plume, the region of aflerburning reduces a lot, and temperature on the ground wall declines rapidly, which can decrease the ablation of the combustion gas to the launch ground.
基金Project supported by the National Natural Science Foundation of China (Nos.50479038 and 50679061)
文摘The turbulent flow of vertical plane wall plume with concentration variation was studied with the finite analytical method. The k-epsilon model with the effect of buoyancy on turbulent kinetic energy and its dissipation rate was adopted. There were similarity solutions in the uniform environment for the system of equations including the equation of continuity, the equation of momentum along the flow direction and concentration, and equations of k, epsilon. The finite analytic method was applied to obtain the similarity solution. The calculated data of velocity, relative density difference, the kinetic energy of turbulence and its dissipation rate distribution for vertical plane plumes are in good agreement with the experimental data at the turbulent Schmidt number equal to 1.0. The variations of their maximum value along the direction of main flow were also given. It shows that the present model is good, i.e., the effect of buoyancy on turbulent kinetic energy and its dissipation rate should be taken into account, and the finite analytic method is effective.
基金supported by the National Natural Science Foundation of China (Nos. 41072045, 41102209)the Research Fund for the Doctoral Program of Higher Education (No. 20090145110001)+1 种基金Nondestructive Analysis Technique and Best Analysis Scheme of Lunar Sample (No. TY3Q20110029)China University of Geosciences (Wuhan) GF Special Research Fund (No. CUGXGF0901)
文摘Marius Hills is a volcanic plateau on the nearside of the Moon. It is of great interest for its high concentration of volcanic features, including domes, cones, ridges, and rilles. However, the morphological and chronological characteristics of this plateau were not well studied due to the low resolution of early mission data. This study describes the detailed morphology of the volcanic features using the latest high spatial resolution images of the Terrain Camera （TC） onboard Selene-1 （10 m/pix） and Narrow Angle Camera （NAC） onboard the Lunar Reconnaissance Orbiter （LRO） （0.5 m/pix）. We report here some new structures such as skylights and remnants of lava tubes. We have divided spectrally homogenous areas with Clementine UVVIS data and did crater size frequency distribution （CSFD） measurements with Lunar Orbiter （LO） IV and TC images in every spectral unit. We first report absolute model ages of 1.10 Ga for Marius basalt 1, 1.49 Ga for Fiamsteed basalt, and 1.46 Ga for Schiaparelli Basalt. In addition, we have identified several younger lava events： they are Marius basalt 2 （814 Ma）, medium to low titanium basalt （949 Ma）, and undifferentiated medium titanium basalt （687 Ma）. Finally, we propose a mantle plume scenario for the formation of Marius Hills, which could solve the inconsistency of previous models.
文摘The conventional atmospheric dispersion models used in China (CRADM), America (HPDM) and Canada (AMS) are investigated. The main differences between the three models are described, and the various aspects of CRADM, HPDM and AMS for same input are compared and discussed. Some problems in application of atmospheric dispersion models to environmental impact assessment are analyzed and suggestions for rivision are proposed. Results show that the Briggs plume rise formula in neutral condition overestimates the real rise due to the fact that the accumulative effect of ambient turbulence on plume is not considered in his model.
文摘A three-dimensional numerical model of the coastal plume in an ideal basin for the western Gulf of Maine of USA, based on the observations, was configured to examine the dynamical properties under the spring riverine, tidal, and wind forcing. The purpose of this paper is to reveal possible effects of different factors on the coastal plume. The control run with a sloping bottom mimicking the western Gulf of Maine reproduced a southward advection speed of 14 km/d, consistent with the observed speed of 13.3 km/d. The plume evolutions due to the two typical wind forcing, upwelling favourable (wind from north) and downwelling favourable (wind from south). were simulated to explain the observations during the spring of 1993. A systematic sensitivity study was also conducted on the following themes: model parameters. dynamic processes, and topography effect.
基金co-funded by a U.S.National Science Foundation(Grant EAR-0538119)to E.Calaisthe Advanced ERC(Grant 290864 RHEOLITH)to E.Burov and A.Koptev+2 种基金the Royal Academy of Netherlands visiting professor grant to E.Burovthe UPMC visiting professor grant to S.Cloetinghperformed on the ERC-funded SGI Ulysse cluster of ISTEP
文摘The East African Rift system （EARS） provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides of the old thick Tanzanian craton embedded in a younger lithosphere. Data on the pre-rifr, syn-rift and post-rift far-field volcanic and tectonic activity show that the EARS formed in the context of the interaction between a deep mantle plume and a horizontally and vertically heterogeneous lithosphere under far-field tectonic extension. We bring quantitative insights into this evolution by implementing high-resolution 3D thermo-mechanical numerical deformation models of a lithosphere of realistic rheology. The models focus on the central part of the EARS. We explore scenarios of plumelithosphere interaction with plumes of various size and initial position rising beneath a tectonically pre-stretched lithosphere. We test the impact of the inherited rheological discontinuities （suture zones） along the craton borders, of the rheological structure, of lithosphere plate thickness variations, and of physical and mechanical contrasts between the craton and the embedding lithosphere. Our experiments indicate that the ascending plume material is deflected by the cratonic keel and preferentially channeled along one of its sides, leading to the formation of a large rift zone along the eastern side of the craton, with significant magmatic activity and substantial melt amount derived from the mantle plume material. We show that the observed asymmetry of the central EARS, with coeval amagmatic （western） and magmatic （eastern） branches, can be explained by the splitting of warm material rising from a broad plume head whose initial position is slightly shifted to the eastern side of the craton. In that case, neither a mechanical weakness of the contact between the craton and the embedding lithosphere nor the presence of second plume are required to produce simulations that match observations. This result reconciles the passive and active rift models and demonstrates the possibility of development of both magmatic and amagmatic rifts in identical geotectonic environments.
文摘The plume interaction above an alternating diffuser in stagnant water is studied with 3D Reynolds-averaged NavierStokes equations （RANS） combined with a buoyancy-extended κ-ε model. The steady three-dimensional turbulent flow and temperature fields are computed by use of the finite volume method on a non-uniform high resolution orthogonal grid. The numerical predictions demonstrate a generic flow pattern for different turbulent heated jet discharges： the buoyant jets on each side of the diffuser first merge to form an essentially two-dimensional plume which bends back toward the diffuser centerline due to a low pressure cavity. In general, an under-pressure exists in the cavity until the plumes merge; the pressure increases to slightly positive afterwards. Two-dimensionality of the scalar and flow field is attained much later than the point of zero pressure. The position of merging point is governed by mainly four parameters - the discharge densimetfic Froude number, the port diameter and space, and the horizontal distance between alternating jet nozzles. A formula from numerical simulations is obtained through regression analysis and it is used to predict the position of plume merging point. The predicted temperature fields are comparable to previous experiments.
