Athanasios Angeloudis | Imperial College London (original) (raw)

Papers by Athanasios Angeloudis

Large-Eddy Simulations (LESs) and experiments were employed to study the influence of water depth... more Large-Eddy Simulations (LESs) and experiments were employed to study the influence of water depth on the hydrodynamics in the wake of a conical island for emergent, shallow, and deeply submerged conditions. The Reynolds numbers based on the island's base diameter for these conditions range from 6500 to 8125. LES results from the two shallower conditions were validated against experimental measurements from an open channel flume and captured the characteristic flow structures around the cone, including the attached recirculation region, vortex shedding, and separated shear layers. The wake was impacted by the transition from emergent to shallow submerged flow conditions with more subtle changes in time-averaged velocity and instantaneous flow structures when the submergence increases further. Despite differences in the breakdown of the separated shear layers, vortex shedding, and the upward flow region on the leeward face (once the cone's apex is submerged), similar flow structures to cylinder flow were observed. These include an arch vortex tilted in the downstream direction and von Karman vortices in the far-wake. Spectra of velocity time series and the drag coefficient indicated that the vortex shedding was constrained by the overtopping flow layer, and thus the shedding frequency decreased as the cone's apex became submerged. Finally, the generalised flow structures in the wake of a submerged conical body are outlined.

The regular and predictable nature of the tide makes the generation of electricity with a tidal l... more The regular and predictable nature of the tide makes the generation of electricity with a tidal lagoon or barrage an attractive form of renewable energy, yet storm surges affect the total water-level. Here we present the first assessment of the potential impact of storm surges on tidal-range power. Water-level data (2000–2012) at nine UK tide gauges, where tidal-range energy is suitable for development (e.g. Bristol Channel), was used to predict power. Storm surge affected annual resource estimates −5% to +3%, due to inter-annual variability, which is lower than other sources of uncertainty (e.g. lagoon design); therefore, annual resource estimation from astronomical tides alone appears sufficient. However, instantaneous power output was often significantly affected (Normalised Root Mean Squared Error: 3%–8%, Scatter Index: 15%–41%) and so a storm surge prediction system may be required for any future electricity generation scenario that includes large amounts of tidal-range generation. The storm surge influence to tidal-range power varied with the electricity generation strategy considered (flooding tide only, ebb-only or dual; both flood and ebb), but with some spatial and temporal variability. The flood-only strategy was most affected by storm surge, mostly likely because tide-surge interaction increases the chance of higher water-levels on the flooding tide.

A methodology associated with the simulation of tidal range projects through a coastal hydrodynam... more A methodology associated with the simulation of tidal range projects through a coastal hydrodynamic model is discussed regarding its capabilities and limitations. Particular focus is directed towards the formulations imposed for the representation of hydraulic structures and the corresponding model boundary conditions. Details of refinements are presented that would be applicable in representing the flow (and momentum flux) expected through tidal range turbines to inform the regional modelling of tidal lagoons and barrages. A conceptual tidal lagoon along the North Wales coast, a barrage across the Severn Estuary and the Swansea Bay Lagoon proposal are used to demonstrate the effect of the refinements for projects of a different scale. The hydrodynamic model results indicate that boundary refinements, particularly in the form of accurate momentum conservation, have a noticeable influence on near-field conditions and can be critical when assessing the environmental impact arising from the schemes. Finally, it is shown that these models can be used to guide and improve tidal impoundment proposals.

The feasibility and sustainable operation of tidal lagoons and barrages has been under scrutiny o... more The feasibility and sustainable operation of tidal lagoons and barrages has been under scrutiny over uncertainties with regards to their environmental impacts, potential interactions and energy output. A numerical modelling methodology that evaluates their effects on the hydro-environment has been refined to consider technical constraints and specifications associated with variable turbine designs and operational sequences. The method has been employed to assess a number of proposals and their combinations within the Bristol Channel and Severn Estuary in the UK. Operational challenges associated with tidal range power plants are highlighted, while also presenting the capabilities of modelling tools tailored to their assessment. Results indicate that as the project scale increases so does its relative hydrodynamic impact, which may compromise annual energy output expectations if not accounted for. However, the manner in which such projects are operated can also have a significant impact on changing the local hydro-environment, including the ecology and morphology. Therefore, it is imperative that tidal range power plants are designed in such a way that they efficiently tap into the renewable energy sources, with minimal interference to the regional hydro-environment through their operation.

In this study three-dimensional numerical models were refined to predict reactive processes in di... more In this study three-dimensional numerical models were refined to predict reactive processes in disinfection contact tanks (CTs). The methodology departs from the traditional performance assessment of contact tanks via Hydraulic Efficiency Indicators as it allows direct simulation of transport and decay of the disinfectant, inactivation of pathogens and accumulation of by-products. The method is applied to study the effects of inlet and compartment design on contact tank performance, with special emphasis on turbulent mixing and minimisation of internal recirculation and short-circuiting. In contrast to the conventional approach of maximizing the length-to-width ratio, the proposed design changes are aimed at addressing and mitigating against adverse hydrodynamic structures, which have historically led to poor hydraulic efficiency in many existing contact tanks. The results suggest that water treatment facilities can benefit from in-depth analyses of the flow and kinetic processes through computational fluid dynamics, resulting in up to 38% more efficient pathogen inactivation and 14% less disinfection by-product formation.

We discuss certain design aspects of tidal lagoons to inform future proposals. We demonstrate the... more We discuss certain design aspects of tidal lagoons to inform future proposals. We demonstrate the tidal lagoon representation within a 0-D and 2-D hydrodynamic modelling framework. We examine the potential of simplified 0-D modelling techniques for operation optimisation. We highlight the extent where 2-D hydrodynamic model power predictions can deviate from 0-D modelling.

Journal of Hydro-envoronment Reseach, Sep 1, 2014

The hydrodynamics and mixing processes in small- and full-scale baffled disinfection tanks are st... more The hydrodynamics and mixing processes in small- and full-scale baffled disinfection tanks are studied experimentally and numerically. Velocity and tracer transport measurements are carried out to quantify the hydrodynamics and to obtain reliable data used to validate a three-dimensional computational fluid dynamics (CFD) model. The flow in the tank under investigation is extensively three-dimensional due to the existing inlet condition of the tank, resulting in short-circuiting and internal recirculation, particularly in the first three compartments. Near the inlet the tracer residence time distribution curve analysis and Hydraulic Efficiency Indicators (HEIs) suggest poor disinfection performance. Further away from the inlet, the flow recovers to a two-dimensional flow and the HEIs improve until the exit of the tank. The computational results demonstrate good agreement between the predicted hydrodynamics and tracer transport with the corresponding experimental data. The numerical model is then employed to investigate the effects of up-scaling of laboratory model findings to a full-scale contact tank. Despite the Froude–Reynolds conflict the full-scale contact tank exhibits similar behaviour to the small-scale tank. The effect of the tank geometry on the disinfection efficiency is demonstrated, highlighting the negative impact of flow three-dimensionality on pathogen inactivation.

Predicting the Disinfection Efficiency Range in Chlorine Contact Tanks through a CFD-Based Approach, Sep 1, 2014

In this study three-dimensional computational fluid dynamics (CFD) models, incorporating appropri... more In this study three-dimensional computational fluid dynamics (CFD) models, incorporating appropriately selected kinetic models, were developed to simulate the processes of chlorine decay, pathogen inactivation and the formation of potentially carcinogenic by-products in disinfection contact tanks (CTs). Currently, the performance of CT facilities largely relies on Hydraulic Efficiency Indicators (HEIs), extracted from experimentally derived Residence Time Distribution (RTD) curves. This approach has more recently been aided with the application of CFD models, which can be calibrated to predict accurately RTDs, enabling the assessment of disinfection facilities prior to their construction. However, as long as it depends on HEIs, the CT design process does not directly take into consideration the disinfection biochemistry which needs to be optimized. The main objective of this study is to address this issue by refining the modelling practices to simulate some reactive processes of interest, while acknowledging the uneven contact time stemming from the RTD curves. Initially, the hydraulic performances of seven CT design variations were reviewed through available experimental and computational data. In turn, the same design configurations were tested using numerical modelling techniques, featuring kinetic models that enable the quantification of disinfection operational parameters. Results highlight that the optimization of the hydrodynamic conditions facilitates a more uniform disinfectant contact time, which correspond to greater levels of pathogen inactivation and a more controlled by-product accumulation.

Modelling of flow, transport and disinfection kinetics in contact tanks, Feb 19, 2014

Water research, 2012

With new water directives imposing strict regulations to reduce the footprint of treatment operat... more With new water directives imposing strict regulations to reduce the footprint of treatment operations and contaminant levels, a performance review of water treatment facilities, including Chlorine Contact Tanks (CCTs) is required. This paper includes a critical appraisal of the international literature on CCT modelling practices to date, aiming to assist the identification of areas requiring further development, in particular, relating to the computational modelling capability and availability of tools to assist hydraulic design and optimisation studies of CCTs. It notes that the hydraulic optimisation practice of poorly designed tanks commenced with experimental studies undertaken in the 1960s and 1970s, which involved mainly two types of studies, namely in-situ tracer tests and laboratory physical modelling. The former has traditionally been conducted to diagnose the hydraulic performance of existing CCTs, typically based on results such as Residence Time Distribution (RTD) curves and values of the Hydraulic Efficiency Indicators (HEIs). The latter has been useful in trial and error testing of the impact of certain design modifications on those results, with suggestions for later improvements of the field scale unit. In the 1980s mathematical and numerical modelling studies started to be used to assist CCT investigations, offering a greater level of detail in a more costeffective manner than equivalent experimentally-based investigations. With the growth of computing power and the popularisation of computational models, the 1990s saw the development and application of Computational Fluid Dynamics (CFD) tools to simulate the hydraulic performance of CCTs, sometimes independently of experimentation, other than by using available data to calibrate and validate modelling predictions. This has led to the current scenario of CFD models being invaluable assistive tools in optimisation studies of CCTs, with the experimentation practice continuing to allow for specific diagnostics and to supply data for the calibration and validation of CFD modelling results. The vast majority of CCT modelling studies published to date have focused on simulating CCT hydrodynamic and conservative solute transport processes. The chlorination kinetics and Disinfection By-Product (DBP) formation have rarely been contemplated in computer modelling studies of CCTs. Commercially available CFD models have not traditionally been applied with this purpose, while research studies undertaken using open source codes to produce tailor-made applications are rare. Aspects that could benefit from further understanding and/or development include the impact of scale when conducting experimentation with prototypes, adequate turbulence closure for a given situation, adequate numerical schemes vis-à-vis CFD model complexity vis-à-vis cost-benefit ratio of simulations and the inclusion of state of the art chlorination kinetics and DBP formation modelling in the CFD tools that can assist modern design and retrofit studies of CCTs.

The performance assessment of water disinfection contact tank (CT) facilities largely relies on H... more The performance assessment of water disinfection contact tank (CT) facilities largely relies on Hydraulic Efficiency Indicators (HEIs) extracted from experimentally derived Residence Time Distribution (RTD) curves. This approach has more recently been aided with the application of Computational Fluid Dynamics (CFD) models, which can be calibrated to predict accurately RTDs, enabling the assessment of disinfection facilities prior to their construction. Despite the advances of experimental and computational analyses, the CT design does not directly take into consideration the disinfection chemistry which needs to be optimized process, as long as it relies on HEIs. In this study a three-dimensional steady-state CFD approach is set-up with appropriately selected kinetic models, describing the processes of disinfectant decay, pathogen inactivation and the formation of potentially carcinogenic Disinfection By-Products (DBPs). Initially, the hydraulic performances of three CT designs using experimental and computational data are reviewed. In turn, the same design configurations are tested using numerical techniques, featuring kinetic models that enable the quantification of disinfection operational parameters. Results highlight that the optimization of hydraulic efficiency facilitates more uniform disinfectant contact times, which correspond to greater levels of pathogen inactivation and a more controlled by-product accumulation.

CFD Study of Flow and Transport Characteristics in Baffled Disinfection Tanks , 2013

With the aim of optimising contact tank design through numerical model simulations, results are p... more With the aim of optimising contact tank design through numerical model simulations, results are presented herein of an experimental and computational fluid dynamics (CFD) study in a scaled laboratory model. Three-dimensional numerical simulations of flow and transport characteristics were conducted using a Reynolds Averaged Navier-Stokes equation approach. Experimental results were obtained through Acoustic Doppler Velocimetry measurements and a series of conservative tracer experiments. Focus is given on turbulent structures and undesirable flow patterns that lead to a reduced disinfection efficiency, through phenomena such as short circuiting and recirculation zones. The laboratory data analysis indicates extensive three-dimensionality as a result of the current inlet geometry with a confirmed negative impact on the disinfection performance of the contact tank model, as demonstrated by Residence Time Distribution curves. Disinfection performance is evaluated through hydraulic efficiency indicators commonly used in the industry to monitor field-scale disinfection facilities. Correlations between CFD and experimental data confirm the adequate reproduction of hydrodynamic conditions and reinforce the predictive capabilities of numerical models as tools to simulate field scale tanks or optimize existing designs.

Large-Eddy Simulations (LESs) and experiments were employed to study the influence of water depth... more Large-Eddy Simulations (LESs) and experiments were employed to study the influence of water depth on the hydrodynamics in the wake of a conical island for emergent, shallow, and deeply submerged conditions. The Reynolds numbers based on the island's base diameter for these conditions range from 6500 to 8125. LES results from the two shallower conditions were validated against experimental measurements from an open channel flume and captured the characteristic flow structures around the cone, including the attached recirculation region, vortex shedding, and separated shear layers. The wake was impacted by the transition from emergent to shallow submerged flow conditions with more subtle changes in time-averaged velocity and instantaneous flow structures when the submergence increases further. Despite differences in the breakdown of the separated shear layers, vortex shedding, and the upward flow region on the leeward face (once the cone's apex is submerged), similar flow structures to cylinder flow were observed. These include an arch vortex tilted in the downstream direction and von Karman vortices in the far-wake. Spectra of velocity time series and the drag coefficient indicated that the vortex shedding was constrained by the overtopping flow layer, and thus the shedding frequency decreased as the cone's apex became submerged. Finally, the generalised flow structures in the wake of a submerged conical body are outlined.

The regular and predictable nature of the tide makes the generation of electricity with a tidal l... more The regular and predictable nature of the tide makes the generation of electricity with a tidal lagoon or barrage an attractive form of renewable energy, yet storm surges affect the total water-level. Here we present the first assessment of the potential impact of storm surges on tidal-range power. Water-level data (2000–2012) at nine UK tide gauges, where tidal-range energy is suitable for development (e.g. Bristol Channel), was used to predict power. Storm surge affected annual resource estimates −5% to +3%, due to inter-annual variability, which is lower than other sources of uncertainty (e.g. lagoon design); therefore, annual resource estimation from astronomical tides alone appears sufficient. However, instantaneous power output was often significantly affected (Normalised Root Mean Squared Error: 3%–8%, Scatter Index: 15%–41%) and so a storm surge prediction system may be required for any future electricity generation scenario that includes large amounts of tidal-range generation. The storm surge influence to tidal-range power varied with the electricity generation strategy considered (flooding tide only, ebb-only or dual; both flood and ebb), but with some spatial and temporal variability. The flood-only strategy was most affected by storm surge, mostly likely because tide-surge interaction increases the chance of higher water-levels on the flooding tide.

A methodology associated with the simulation of tidal range projects through a coastal hydrodynam... more A methodology associated with the simulation of tidal range projects through a coastal hydrodynamic model is discussed regarding its capabilities and limitations. Particular focus is directed towards the formulations imposed for the representation of hydraulic structures and the corresponding model boundary conditions. Details of refinements are presented that would be applicable in representing the flow (and momentum flux) expected through tidal range turbines to inform the regional modelling of tidal lagoons and barrages. A conceptual tidal lagoon along the North Wales coast, a barrage across the Severn Estuary and the Swansea Bay Lagoon proposal are used to demonstrate the effect of the refinements for projects of a different scale. The hydrodynamic model results indicate that boundary refinements, particularly in the form of accurate momentum conservation, have a noticeable influence on near-field conditions and can be critical when assessing the environmental impact arising from the schemes. Finally, it is shown that these models can be used to guide and improve tidal impoundment proposals.

The feasibility and sustainable operation of tidal lagoons and barrages has been under scrutiny o... more The feasibility and sustainable operation of tidal lagoons and barrages has been under scrutiny over uncertainties with regards to their environmental impacts, potential interactions and energy output. A numerical modelling methodology that evaluates their effects on the hydro-environment has been refined to consider technical constraints and specifications associated with variable turbine designs and operational sequences. The method has been employed to assess a number of proposals and their combinations within the Bristol Channel and Severn Estuary in the UK. Operational challenges associated with tidal range power plants are highlighted, while also presenting the capabilities of modelling tools tailored to their assessment. Results indicate that as the project scale increases so does its relative hydrodynamic impact, which may compromise annual energy output expectations if not accounted for. However, the manner in which such projects are operated can also have a significant impact on changing the local hydro-environment, including the ecology and morphology. Therefore, it is imperative that tidal range power plants are designed in such a way that they efficiently tap into the renewable energy sources, with minimal interference to the regional hydro-environment through their operation.

In this study three-dimensional numerical models were refined to predict reactive processes in di... more In this study three-dimensional numerical models were refined to predict reactive processes in disinfection contact tanks (CTs). The methodology departs from the traditional performance assessment of contact tanks via Hydraulic Efficiency Indicators as it allows direct simulation of transport and decay of the disinfectant, inactivation of pathogens and accumulation of by-products. The method is applied to study the effects of inlet and compartment design on contact tank performance, with special emphasis on turbulent mixing and minimisation of internal recirculation and short-circuiting. In contrast to the conventional approach of maximizing the length-to-width ratio, the proposed design changes are aimed at addressing and mitigating against adverse hydrodynamic structures, which have historically led to poor hydraulic efficiency in many existing contact tanks. The results suggest that water treatment facilities can benefit from in-depth analyses of the flow and kinetic processes through computational fluid dynamics, resulting in up to 38% more efficient pathogen inactivation and 14% less disinfection by-product formation.

We discuss certain design aspects of tidal lagoons to inform future proposals. We demonstrate the... more We discuss certain design aspects of tidal lagoons to inform future proposals. We demonstrate the tidal lagoon representation within a 0-D and 2-D hydrodynamic modelling framework. We examine the potential of simplified 0-D modelling techniques for operation optimisation. We highlight the extent where 2-D hydrodynamic model power predictions can deviate from 0-D modelling.

Journal of Hydro-envoronment Reseach, Sep 1, 2014

The hydrodynamics and mixing processes in small- and full-scale baffled disinfection tanks are st... more The hydrodynamics and mixing processes in small- and full-scale baffled disinfection tanks are studied experimentally and numerically. Velocity and tracer transport measurements are carried out to quantify the hydrodynamics and to obtain reliable data used to validate a three-dimensional computational fluid dynamics (CFD) model. The flow in the tank under investigation is extensively three-dimensional due to the existing inlet condition of the tank, resulting in short-circuiting and internal recirculation, particularly in the first three compartments. Near the inlet the tracer residence time distribution curve analysis and Hydraulic Efficiency Indicators (HEIs) suggest poor disinfection performance. Further away from the inlet, the flow recovers to a two-dimensional flow and the HEIs improve until the exit of the tank. The computational results demonstrate good agreement between the predicted hydrodynamics and tracer transport with the corresponding experimental data. The numerical model is then employed to investigate the effects of up-scaling of laboratory model findings to a full-scale contact tank. Despite the Froude–Reynolds conflict the full-scale contact tank exhibits similar behaviour to the small-scale tank. The effect of the tank geometry on the disinfection efficiency is demonstrated, highlighting the negative impact of flow three-dimensionality on pathogen inactivation.

Predicting the Disinfection Efficiency Range in Chlorine Contact Tanks through a CFD-Based Approach, Sep 1, 2014

In this study three-dimensional computational fluid dynamics (CFD) models, incorporating appropri... more In this study three-dimensional computational fluid dynamics (CFD) models, incorporating appropriately selected kinetic models, were developed to simulate the processes of chlorine decay, pathogen inactivation and the formation of potentially carcinogenic by-products in disinfection contact tanks (CTs). Currently, the performance of CT facilities largely relies on Hydraulic Efficiency Indicators (HEIs), extracted from experimentally derived Residence Time Distribution (RTD) curves. This approach has more recently been aided with the application of CFD models, which can be calibrated to predict accurately RTDs, enabling the assessment of disinfection facilities prior to their construction. However, as long as it depends on HEIs, the CT design process does not directly take into consideration the disinfection biochemistry which needs to be optimized. The main objective of this study is to address this issue by refining the modelling practices to simulate some reactive processes of interest, while acknowledging the uneven contact time stemming from the RTD curves. Initially, the hydraulic performances of seven CT design variations were reviewed through available experimental and computational data. In turn, the same design configurations were tested using numerical modelling techniques, featuring kinetic models that enable the quantification of disinfection operational parameters. Results highlight that the optimization of the hydrodynamic conditions facilitates a more uniform disinfectant contact time, which correspond to greater levels of pathogen inactivation and a more controlled by-product accumulation.

Modelling of flow, transport and disinfection kinetics in contact tanks, Feb 19, 2014

Water research, 2012

With new water directives imposing strict regulations to reduce the footprint of treatment operat... more With new water directives imposing strict regulations to reduce the footprint of treatment operations and contaminant levels, a performance review of water treatment facilities, including Chlorine Contact Tanks (CCTs) is required. This paper includes a critical appraisal of the international literature on CCT modelling practices to date, aiming to assist the identification of areas requiring further development, in particular, relating to the computational modelling capability and availability of tools to assist hydraulic design and optimisation studies of CCTs. It notes that the hydraulic optimisation practice of poorly designed tanks commenced with experimental studies undertaken in the 1960s and 1970s, which involved mainly two types of studies, namely in-situ tracer tests and laboratory physical modelling. The former has traditionally been conducted to diagnose the hydraulic performance of existing CCTs, typically based on results such as Residence Time Distribution (RTD) curves and values of the Hydraulic Efficiency Indicators (HEIs). The latter has been useful in trial and error testing of the impact of certain design modifications on those results, with suggestions for later improvements of the field scale unit. In the 1980s mathematical and numerical modelling studies started to be used to assist CCT investigations, offering a greater level of detail in a more costeffective manner than equivalent experimentally-based investigations. With the growth of computing power and the popularisation of computational models, the 1990s saw the development and application of Computational Fluid Dynamics (CFD) tools to simulate the hydraulic performance of CCTs, sometimes independently of experimentation, other than by using available data to calibrate and validate modelling predictions. This has led to the current scenario of CFD models being invaluable assistive tools in optimisation studies of CCTs, with the experimentation practice continuing to allow for specific diagnostics and to supply data for the calibration and validation of CFD modelling results. The vast majority of CCT modelling studies published to date have focused on simulating CCT hydrodynamic and conservative solute transport processes. The chlorination kinetics and Disinfection By-Product (DBP) formation have rarely been contemplated in computer modelling studies of CCTs. Commercially available CFD models have not traditionally been applied with this purpose, while research studies undertaken using open source codes to produce tailor-made applications are rare. Aspects that could benefit from further understanding and/or development include the impact of scale when conducting experimentation with prototypes, adequate turbulence closure for a given situation, adequate numerical schemes vis-à-vis CFD model complexity vis-à-vis cost-benefit ratio of simulations and the inclusion of state of the art chlorination kinetics and DBP formation modelling in the CFD tools that can assist modern design and retrofit studies of CCTs.

The performance assessment of water disinfection contact tank (CT) facilities largely relies on H... more The performance assessment of water disinfection contact tank (CT) facilities largely relies on Hydraulic Efficiency Indicators (HEIs) extracted from experimentally derived Residence Time Distribution (RTD) curves. This approach has more recently been aided with the application of Computational Fluid Dynamics (CFD) models, which can be calibrated to predict accurately RTDs, enabling the assessment of disinfection facilities prior to their construction. Despite the advances of experimental and computational analyses, the CT design does not directly take into consideration the disinfection chemistry which needs to be optimized process, as long as it relies on HEIs. In this study a three-dimensional steady-state CFD approach is set-up with appropriately selected kinetic models, describing the processes of disinfectant decay, pathogen inactivation and the formation of potentially carcinogenic Disinfection By-Products (DBPs). Initially, the hydraulic performances of three CT designs using experimental and computational data are reviewed. In turn, the same design configurations are tested using numerical techniques, featuring kinetic models that enable the quantification of disinfection operational parameters. Results highlight that the optimization of hydraulic efficiency facilitates more uniform disinfectant contact times, which correspond to greater levels of pathogen inactivation and a more controlled by-product accumulation.

CFD Study of Flow and Transport Characteristics in Baffled Disinfection Tanks , 2013

With the aim of optimising contact tank design through numerical model simulations, results are p... more With the aim of optimising contact tank design through numerical model simulations, results are presented herein of an experimental and computational fluid dynamics (CFD) study in a scaled laboratory model. Three-dimensional numerical simulations of flow and transport characteristics were conducted using a Reynolds Averaged Navier-Stokes equation approach. Experimental results were obtained through Acoustic Doppler Velocimetry measurements and a series of conservative tracer experiments. Focus is given on turbulent structures and undesirable flow patterns that lead to a reduced disinfection efficiency, through phenomena such as short circuiting and recirculation zones. The laboratory data analysis indicates extensive three-dimensionality as a result of the current inlet geometry with a confirmed negative impact on the disinfection performance of the contact tank model, as demonstrated by Residence Time Distribution curves. Disinfection performance is evaluated through hydraulic efficiency indicators commonly used in the industry to monitor field-scale disinfection facilities. Correlations between CFD and experimental data confirm the adequate reproduction of hydrodynamic conditions and reinforce the predictive capabilities of numerical models as tools to simulate field scale tanks or optimize existing designs.