Turbulent Energy Dissipation Research Articles

Estimation of mean turbulent kinetic energy and temperature variance dissipation rates using a spectral chart method

A method aimed at estimating εk and εθ, respectively, the mean dissipation rates of turbulent kinetic energy k and half the temperature variance θ2/2, is developed for slightly heated turbulent flows of air. It is limited to a Prandtl number near unity and applicable to flows where temperature can be treated as a passive scalar. A significant advantage of the method is that εk and εθ can both be estimated from the measurement of a temperature frequency spectrum, Gθθ(f). The method relies on the collapse in the dissipative range of one-dimensional temperature spectra, ϕθ(k1η), when normalized with εθ, εk, and ν. This collapse ensues from a similarity analysis of scale-by-scale budgets of the second-order structure function for the temperature. A generic spectrum ϕθG(k1η), defined in the wavenumber range 0.07 ≤ k1η ≤ 0.7, is used to construct a spectral chart. The method has been tested in several flows and found to be reliable. In particular, it is tested on the axis of a slightly heated round jet, where εk and εθ can be estimated accurately via the budgets of k and θ2/2, and the agreement between these estimates and the spectral chart results is almost perfect.

Structure functions and invariants of the anisotropic Reynolds stress tensor in turbulent flows on water-worked gravel beds

In this paper, a statistical description of turbulence in flow on a water-worked gravel-bed is presented by applying the laws of turbulence in conjunction with the double-averaging methodology. To this end, a laboratory experiment was performed, in which the gravel-bed was worked by flowing water. From the Taylor frozen-in approximation, the energy spectra of streamwise velocity fluctuation reveal the existence of the inertial subrange (lying between the energy containing and the dissipation ranges), where the turbulent kinetic energy (TKE) dissipation rate is constant. It is revealed that, in this range, Kolmogorov’s 4/5-law for the spatial increments of streamwise velocity is valid, thus allowing an accurate estimation of the TKE dissipation rate. Although Monin–Yaglom’s 4/3-law for the third-order mixed structure function provides a behavior similar to that of Kolmogorov’s 4/5-law, the estimation of the TKE dissipation rate by Monin–Yaglom’s 4/3-law is not quite accurate, owing to the departure from the isotropic turbulence at large scales. Therefore, the present study demonstrates the validity of this statistical approach (Kolmogorov’s 4/5-law) to investigate the turbulence at small scales. Besides, the data plots for an anisotropy invariant map suggest that near-bed anisotropic turbulence tends to reduce to the three-dimensional isotropic turbulence with an increase in the vertical distance, indicating a relaxation of the effects of bed roughness on anisotropic turbulence toward the free surface.

Assessment of large-scale forcing in isotropic turbulence using a closed Kármán–Howarth equation

We attempt to model the effects of large-scale forcing on the statistical behavior of small scales in isotropic turbulence. More specifically, the effect of large-scale forcing on the second-order velocity structure function, S2, in the region beyond the dissipative range, is analyzed via the transport equation for S2 where a closure model for S3, the third-order velocity structure function, is introduced. The model [L. Djenidi and R. A. Antonia, Fluid Turbulence Applications in Both Industrial and Environmental Topics, Marseille, 9–11 July, 2019, https://fab60.sciencesconf.org/] is based on a gradient type with an eddy-viscosity formulation and has the following expression: S3=−CS3(S2)2ϵ¯∂S2∂r, where ϵ¯ is the mean rate of the turbulent kinetic energy dissipation, r is the spatial increment, and CS3 is a constant. The closed S2-transport equation is further exploited to derive a model for S2 for scales beyond the dissipative range. The model for S2 takes the form S2=CK(ϵrr)23 with ϵr=ϵ¯1−Br/Reλ1/2, where CK is a constant, Reλ is the Taylor microscale Reynolds number, and the function Br accounts for the effect of the large scales. The numerical solutions of the S2 equation and the predictions based on the model for S2 agree very well with direct numerical simulation data for steady-state forced homogeneous and isotropic turbulence. The solutions of the S2-transport equation without large-scale forcing show that S2 behaves like (ϵ¯r)2/3. When forcing is applied, S2 deviates from this behavior. However, increasing the Reynolds number tends to restore this behavior over an increasing range of scales. This is also observed in the predictions of the model for S2.

Heat transfer optimization through new form of pin type of finned tube heat exchangers using the exergy and energy analysis

Abstract In the present work, computational fluid dynamics method is used to simulate the three dimensional turbulent thermal energy transfer and fluid flow through the new types of the finned tube heat exchangers. The realizable turbulent kinetic energy - turbulent kinetic energy dissipation model is selected as the turbulence model because it has the best results compared to the other turbulence models with the experimental data. After the simulation the energy and exergy analysis are performed and a multi-objective model is defined to obtain the optimal and critical values of the operational and geometrical parameters. Furthermore, equations are suggested for estimation the three objective parameters i.e. thermal effectiveness, dimensionless exergy loss and dimensionless work. Results also indicate, the dimensionless exergy loss is optimum at Re=8333 and Pr=10.63. Furthermore, it was found, the optimum value for the transverse pitch is equal to 3.52, when the objective parameters are the thermal effectiveness and the dimensionless exergy loss.

CFD Research on the Influence of 45° Disk Turbine Agitator Blade Diameter on the Solid–Liquid Mixing Characteristics of the Cone-Bottom Stirred Tank

A numerical simulation of a solid–liquid mixture concentration field in a cone-bottom stirred tank (diameter D = 150 mm) was conducted using computational fluid dynamics (CFD). The influence of the 45° disk turbine impeller diameter on the mixing time number of solid–liquid mixture, mixing energy per unit volume, concentration standard deviation, turbulence energy and turbulent dissipation rate as well as solid just-suspended impeller speed was analyzed. The Eulerian two-fluid model was employed along with the standard k–e turbulence model to simulate the turbulent solid–liquid flow in the cone-bottom stirred tank. A multiple reference frame approach was used to simulate the impeller rotation in a fully baffled reactor. The Fluent® 14.5 commercial CFD software was employed for the transient simulation. The radial and tangential velocities at the outer edge of the impeller along the blade width were compared with the experimental data of Wu and Patterson (Chem Eng Sci 44:2207–2221, 1989), Mahouast et al. (Entropy 133:7–17, 1987) and Kemoun et al. (IChemE Symp Ser 136:399–406, 1994). The further extended computational model could well predict the influence of impeller diameter on the solid–liquid mixing characteristics.

Numerical investigation of energy loss in a centrifugal pump through kinetic energy dissipation theory

In this study, energy loss within a centrifugal pump is investigated by post-processing three-dimensional unsteady flow field through kinetic energy dissipation theory. The three-dimensional unsteady flow field is predicted by solving unsteady Reynolds-averaged Navier–Stokes equations. The kinetic energy dissipation consists of three parts: averaged kinetic energy dissipation, turbulent kinetic energy dissipation, and near-wall revised kinetic energy dissipation. The total value variations of three kinetic energy dissipations in the centrifugal pump with flowrate are investigated and compared. Results show that with the increase in flowrate, the total near-wall revised kinetic energy dissipation gradually increases, the total turbulent kinetic energy dissipation first gradually decreases and then gradually increases, and reaches the minimum value at the design flowrate. The total averaged kinetic energy dissipation is less than the total turbulent and the total near-wall revised kinetic energy dissipations, and the total near-wall revised kinetic energy dissipation is larger than the total turbulent kinetic energy dissipation when the flowrate is larger than 0.75 Qdes. The space variation of the near-wall revised kinetic energy dissipation with flowrate shows that large near-wall revised kinetic energy dissipation mainly occurs at the volute and transfers from the small cross-section casing to large cross-section casing and discharge pipe with the increase in flowrate. The space variations of the turbulent kinetic energy dissipation with time for three flowrates are also discussed. Results indicate that large turbulent kinetic energy dissipation near the volute tongue evidently changes with the rotation of the impeller, particularly in 0.5 Qdes. The large turbulent kinetic energy dissipation gradually expands to the pressure side of the blade when the volute tongue gradually approaches the middle of the impeller blade passage. The large turbulent kinetic energy dissipation transfers from the impeller inlet and outlet to the volute tongue and discharge pipe with the increase in flowrate. The findings of this study can serve as guide to improve the design of centrifugal pumps.

Spatial structure of turbulent mixing inferred from historical CTD datasets in the Indonesian seas

Turbulent kinetic energy dissipation rates and vertical diffusivities in the Indonesian seas are inferred from historical CTD measurements gathering for the first time data from Indonesian and international cruises. Dissipation rates are inferred from the CTD using an improved Thorpe scale method, which is validated against microstructure measurements. Elevated dissipation rates ~[10−6–10−7] m2 s−3, were observed in the near field stations, such as in the straits, narrowing passages and shallowing topography where internal tides are generated and Indonesian throughflow (ITF) is intense, while lower dissipation rates ~[10−8–10−10] m2 s−3 were observed in the far field stations and below the pycnocline. The main mixing hot spots are located in the Labani Channel and shallowing topography of the Dewakang waters for the western route of ITF, i.e. the passage that connects the north Pacific source via Sulawesi Sea, Makassar Strait and Flores Sea; in the straits of Halmahera, Lifamatola, and Buru for the eastern route of ITF, i.e. the passage that connects the south Pacific source via Halmahera Sea, Maluku Sea, Seram Sea; and in the ITF exit passages, i.e. the Lombok, Sape and Ombai Straits. The eastern route is more dissipative than the western route, which is consistent with the stronger erosion of the salinity peak of the Pacific waters along the eastern route. We found that tidal variations influence the dissipation rates and diffusivities as has been suggested from the yoyo profiling datasets. The spatial pattern of dissipation rates inferred from the high-resolution 3D hydrodynamics model output of Nagai and Hibiya (2015) shows a general agreement with the observations in the location of the mixing hot spots and suggests that the M2 internal tide is the dominant factor driving the turbulent kinetic energy dissipation rates in the Indonesian seas. Yet the model also shows a bias toward lower dissipation rate in the pycnocline, that we attribute to the lack of representation of the ITF and mesoscale circulation and a bias toward higher dissipation rate in the weak mixing region, suggesting an overestimation of the background dissipation rate in calm waters.

Anti-clogging performance optimization for dentiform labyrinth emitters

It is of great scientific significance to reveal the flow characteristics of dentiform emitters and to optimize the channel structure of emitters to improve the anti-clogging properties of emitters, which contribute to improving the working performance of irrigation systems. The study was carried out using computational fluid dynamics (CFD) simulations, combined with the physical test in the laboratory. First, this paper analyzes the distributions of flow velocity, kinetic energy in turbulence, and physical particle trajectories inside the different structural emitters based on CFD simulations, and based on the simulation results, a dentiform emitter optimization scheme was proposed, and two-channel structures, including the structurally improved emitter, were arranged to conduct indoor tests for verification. The result shows that the maximum kinetic energy in turbulence in the flow channel appeared in the main flow area and that the area of strongest energy dissipation in turbulence was at the tooth tip. The main flow area was largest for the emitter with the triangular channel, and the turbulence energy of the low-speed region was highest for the circular trapezoidal structure. The results suggested a scheme for further optimization of the dentiform emitter. For the optimized channel structure, the maximum value of turbulent kinetic energy was increased by about 19–101% compared with the other four flow channels. The area of the main flow region and the kinetic energy in turbulence in the low-speed area in the emitter were increased. In addition, the range of kinetic energy in turbulence was increased by 52–200% in the low-speed region of the channel. The transport rate of physical particles was increased, and the transport distance and residence time of the particles were reduced. The physical test results show that the optimized channel structure emitter achieved a decrease in the clogging probability compared with the other four structures. Therefore, increasing the area of the main flow region and the low-speed area in the flow channel is an effective physical way of physically improving the anti-clogging performance of the emitter.

Evaluation of mixing effect and shear stress of different impeller combinations on nemadectin fermentation

Mass transfer and shear force have significant effects on nemadectin production by Streptomyces cyaneogriseus ssp. noncyanogenus. They are always the conflict-ridden problems in nemadectin fermentation process. In this study, the flow field characteristics under different impeller combinations were quantitatively evaluated in 5 L stirred-tank bioreactor through the laser particle image velocimetry (PIV) system. Results demonstrated that the radial-axial impeller combinations with the time average velocity at 0.38-0.54 Utip, the turbulent kinetic energy dissipation rate at 6.4–10.6 ε/N3D2, and the shear stress rate was 40-150 s−1, were more conductive to cell growth, nemadectin biosynthesis, cell’s activity, respiratory metabolism than other combinations. The highest nemadectin yield was evaluated up to 1543.3 ± 18.5 μg/mL, which was 31.68 % higher than that of the radial flow impeller combinations. This study provided the important guideline for the selection impeller combinations’ on large-scale nemadectin production.

Dissipation of Turbulent Kinetic Energy in the Oscillating Bottom Boundary Layer of a Large Shallow Lake

AbstractMixing rates and biogeochemical fluxes are commonly estimated from the rate of dissipation of turbulent kinetic energy ε as measured with a single instrument and processing method. However, differences in measurements of ε between instruments/methods often vary by one order of magnitude. In an effort to identify error in computing ε, we have applied four common methods to data from the bottom boundary layer of Lake Erie. We applied the second-order structure function method (SFM) to velocity measurements from an acoustic Doppler current profiler, using both canonical and anisotropy-adjusted Kolmogorov constants, and compared the results with those computed from the law of the wall, Batchelor fitting to temperature gradient microstructure, and inertial subrange fitting to acoustic Doppler velocimeter data. The ε from anisotropy-adjusted constants in SFM increased by a factor of 6 or more at 0.2 m above the bed and showed a better agreement with microstructure and inertial method estimations. The maximum difference between SFM ε, computed using adjusted and canonical constants, and microstructure values was 25% and 50%, respectively. This difference was 30% and 55%, respectively, for those from inertial subrange fitting at times of high-intensity turbulence (Reynolds number at 1 m above the bed of more than 2 × 104). Comparison of the SFM ε to those from law of the wall was often poor, with errors as large as one order of magnitude. From the considerable improvement in ε estimates near the bed, anisotropy-adjusted Kolmogorov constants should be applied to compute dissipation in geophysical boundary layers.

Influence of Sediment Mobility on Universal von Kármán Coefficient k and Traversing Length of Eddy in Fluvial Streams

Sediment mobility in stream corroborates many significant mechanisms in terms of interactions of transported particles in the carrier fluid flows. In general, the sediment entrainment in stream refers to temporal and continual motion of non-cohesive grains. This phenomenon significantly influences the near-bed turbulent flow characteristics in streams. Laboratory experiments were conducted in a rectangular open-channel flume of 15 m long, 0.90 m wide and 0.75 m deep fitted with side glass walls and the study is concerned with the determination of von Karman coefficient with non-cohesive bed-load to strive the eddy traversing length, sizes and TKE dissipation rate close to the bed. Two modes of experimental conditions are considered: (1) immobile-bed with no sediment transport known as clear-water flows; and (2) continuous weak bed-load sediment transport, without bed-forms development refer to a mobile-bed flows. In both cases, the sediment beds should remain flat and hydraulically rough. The experimental result reveals that the von Karman coefficient goes down in the traditional log-law of wall in mobile-bed streams with respect to the flow over an immobile bed. A close observation in sediment mobility due to bed load transport shows the reduction in traversing length of an eddy and increment in near-bed eddy size. The increment in near-bed eddy sizes are attributed to the reduction in turbulent kinetic energy dissipation rate close to the stream bed.

Numerical Simulations of Two-Layer Flow past Topography. Part II: Lee Vortices

Abstract This study considers a two-layer fluid with constant density in each layer connected by a layer of continuously varying density for flows past topography in which hydraulic jumps with lee vortices are expected based on shallow-water theory. Numerical integrations of the Navier–Stokes equations at a Reynolds number high enough for a direct numerical simulation of turbulent flow allow an examination of the internal mechanics of the turbulent leeside hydraulic jump and how this mechanics is related to lee vortices. Analysis of the statistically steady state shows that the original source of lee-vortex vertical vorticity is through the leeside descent of baroclinically produced spanwise vorticity associated with the hydraulic jump. This spanwise vorticity is tilted to the vertical at the spanwise extremities of the leeside hydraulic jump. Turbulent energy dissipation in flow through the hydraulic jump allows this leeside vertical vorticity to diffuse and extend downstream. The present simulations also suggest a geometrical interpretation of lee-vortex potential-vorticity creation, a concept central to interpretations of lee vortices based on the shallow-water equations.

Neap-spring variability of tidal dynamics in the Northern Arabian Gulf

Small-scale (periods < 24 h and horizontal length < 10 km) hydrodynamics are significantly influenced by tides in the Northern Arabian Gulf (NAG). Here we characterize, for the first time, the neap-spring variability of tidal currents and mixing in the NAG from field observations. During the experiment between 14–28 July 2017, measurements in the near bottom layer (~1.5–6.5 m above bottom) show: (1) semi-diurnal horizontal velocities induced by tides, with a maximum horizontal speed of ~0.5 m/s; (2) quarter-diurnal cycles in turbulent kinetic energy (TKE) dissipation rates, with inequalities between the daily two floods and two ebbs; (3) well-correlated relations between turbulent diffusivity and gradient Richardson number. Both current velocities and mixing intensity near the bottom increased from neap to spring tides: the mean horizontal speeds increased from 0.18 to 0.26 m/s; the mean TKE dissipation rates increased from 2.2 × 10-7 to 5.5 × 10-7 W/kg and the mean stratification decreased from 2.1 × 10-5 to 5.5 × 10-6 s-2. Thus, the enhanced near bottom turbulent mixing is likely to contribute more significantly to the vertical transports of nutrients and sediments during spring tides in this region. The mean tidal power input (2.6 × 10-2 W/m2), was found to be one order of magnitude larger than the mean wind power input (1.1 × 10-3 W/m2) with ~39% of the tidal energy being dissipated locally by turbulent mixing near the bottom.

Upper edge of chaos and the energetics of transition in pipe flow

In the past two decades, our understanding of the transition to turbulence in shear flows with linearly stable laminar solutions has greatly improved. Regarding the susceptibility of the laminar flow, two concepts have been particularly useful: the edge states and the minimal seeds. In this nonlinear picture of the transition, the basin boundary of turbulence is set by the edge state's stable manifold and this manifold comes closest in energy to the laminar equilibrium at the minimal seed. We begin this paper by presenting numerical experiments in which three-dimensional perturbations are too energetic to trigger turbulence in pipe flow but they do lead to turbulence when their amplitude is reduced. We show that this seemingly counter-intuitive observation is in fact consistent with the fully nonlinear description of the transition mediated by the edge state. In order to understand the physical mechanisms behind this process, we measure the turbulent kinetic energy production and dissipation rates as a function of the radial coordinate. Our main observation is that the transition to turbulence relies on the energy amplification away from the wall, as opposed to the turbulence itself, whose energy is predominantly produced near the wall. This observation is further supported by the similar analyses on the minimal seeds and the edge states. Furthermore, we show that the time-evolution of production-over-dissipation curves provide a clear distinction between the different initial amplification stages of the transition to turbulence from the minimal seed.

Turbulent modelling analysis of saturated steam flow in curved convergent divergent nozzle

The objective of this study is to analyze turbulent flow characteristics of turbulence modeling in Steam Curved Converging Diverging Nozzle. The three turbulence models have been conducted to simulate flow characteristics using k-ε standard, k-ε Renormalization Group (RNG), and Reynolds Stress Model (RSM). Fluid dynamics parameters such as pressure, velocity, and/or density have been analyzed graphically to know the more suitable model. The k- k-ε STD and RNG show give the similar profile of the turbulent kinetic energy (k) and energy dissipation rate (ε) that is differ with the RSM model. After throat position (position 0.67 m) the k-k-ε STD and RNG give the magnitude more than 1200 (m2/s2) for its turbulent kinetic energy and more than 3.2E06 (m2/s3) for its energy dissipation rate. The RSM model give the lowest values which far below 200 (m2/s2) for turbulent kinetic energy and below 2E05 (m2/s3) for energy dissipation rate. The turbulence modeling analysis of steam saturated flow in plane-curved nozzle present the increasing steam velocity about 3 Ma for 200 kPa steam inlet.

Experimental study of surface buoyant jets in crossflow

The dispersion of surface jets in crossflows such as rivers or channels can cause critical environmental problems in the form of chemical or thermal pollution of these water bodies. The turbulent flow structures occurring in such crossflows play an important role in the mixing of surface jets with the surrounding water bodies. In this study, experimental measurements of the time history of the 3-D velocity field were conducted to better understand the flow structure of surface jets in crossflow conditions. Stereoscopic Particle Image Velocimetry was used to measure the instantaneous spatial and temporal velocity distribution downstream of the jet’s discharge point. In addition to the mean velocity distribution, turbulent flow characteristics such as the turbulent kinetic energy ( $$k$$ ), turbulent kinetic energy dissipation rate ( $$\epsilon$$ ), and turbulent eddy viscosity ( $$\nu_{t}$$ ) were calculated. The formation and evolution of a vortex in the surface jet’s flow structure was detected over the measurement zone. The vortex in the surface jets in crossflow resembled to half of the vortices in a counter-rotating vortex pair (CVP) of submerged jets in crossflows. It can be inferred that the water surface performed like a plane of symmetry.

Observational Evidence of Surface Wave‐Generated Strong Ocean Turbulence

AbstractBy using an acoustic Doppler velocimeter mounted on the seabed of the continental shelf of the northern South China Sea, high frequency velocity fluctuations were measured for 4.5 days. The turbulent kinetic energy dissipation rate was estimated. During the observation, the strong ocean response to Typhoon Rammasun was recorded to compare the turbulent characteristics before and during the typhoon. The results show that the turbulence near the seabed is mainly generated by the tidal current shear and exhibits a quarter diurnal variation during the period before the typhoon. During the typhoon period, the dissipation rate ε dramatically increased from 1 × 10−6 to 1 × 10−2 m2 s−3 within a short time, and the significant wave height and the surface wave orbital velocity showed the same tendency. This finding suggests that the turbulence is dominantly generated by the surface waves near the seabed.

Observations of Near-Surface Mixing Behind a Headland

Field observations were collected near the mouth of the Bagaduce River, Maine, in order to understand how complex features affect the intratidal and lateral variability of turbulence and vertical mixing. The Bagaduce River is a low-inflow, macrotidal estuary that features tidal islands, tidal flats and sharp channel bends. Profiles of salinity, temperature, and turbulent kinetic energy dissipation (ε) were collected for a tidal cycle across the estuary with a microstructure profiler. Lateral distributions of current velocities were obtained with an acoustic doppler current profiler. Results showed intratidal asymmetries in bottom-generated vertical eddy diffusivity and viscosity, with larger values occurring on ebb (Kz: 10−2 m2; Az: 10−2 m2/s) compared to flood (Kz: 10−5 m2/s; Az: 10−4 m2/s). Bottom-generated mixing was moderated by the intrusion of stratified water on flood, which suppressed mixing. Elevated mixing (Kz: 10−3 m2; Az: 10−2.5 m2/s) occurred in the upper water column in the lee of a small island and was decoupled from the bottom layer. The near-surface mixing was a product of an eddy formed downstream of a headland, which tended to reinforce vertical shear by laterally straining streamwise velocities. These results are the first to show near-surface mixing caused by vertical vorticity induced by an eddy, rather than previously reported streamwise vorticity associated with lateral circulation.

Extreme events of turbulent kinetic energy production and dissipation in turbulent channel flow: particle image velocimetry measurements

ABSTRACTIt has long been believed that most turbulent kinetic energy (TKE) dissipation occurs in the near-wall region between ejection and sweep events, i.e. beneath near-wall quasi-streamwise (Q-S) vortices, where wall-normal velocity fluctuations are locally zero. Contrary to this view, our experiments, carried out in a fully developed turbulent channel flow at Reτ = 205 by high-speed planar particle image velocimetry, show that the most intensive dissipative events occurring in the viscous sublayer are associated with very rare sweep events originating in the buffer region rather than with the ejections. We show that these rare events are the result of strong rotational motion of Q-S vortices which cause strong shear flow in the lower region of its downward side. Curiously, the same events are responsible for extreme TKE production taking place in the buffer region where its maximum is observed.

Modelling Stilling Basins for Sewage Networks

Concrete elements play an effective role in stilling basin design in terms of enhancing the dissipation of energy to prevent immoderate scouring of downstream structures. Proper appurtenances, such as wedge-shaped splitter blocks, baffle walls, inverted t-sections, rectangular walls, inverted L sections, and impact walls, are thus utilised with circular pipe outlets to create stilling basins that are shorter yet more effective, and thus more economical. This research was based on numerical analysis of stilling basins using FLOW-3D software; the resulting Froude numbers were compared with the Froude number of a case study, a stilling basin manhole created by the Karbala Government. This research thus examined the influence of Froude number, the arrangement and location of dissipators, and the height of the pipe inlet under different hydraulic condition in order to better simulate stilling basin models. The turbulent energy dissipation was found to vary from 16% to 85%. The results from the models showed that L-sections offered maximum turbulent energy dissipation (ΔE/E1), while the rectangular wall shape gave minimum turbulent energy dissipation (ΔE/E1). It was also observed that the maximum turbulent kinetic energy almost always occurred in the initial sections, with flow becoming generally less turbulent at the end sections. Thus, at the end of all stilling basins, the turbulent kinetic energy dissipation and turbulent kinetic energy profiles became more uniform. The proposed numerical simulation using FLOW-3D was shown to be a reliable tool for predicting and discussing the turbulent energy dissipation in stilling basins. Further conclusions included the fact that the maximum turbulent energy dissipation (ΔE/E1) increases as values of Fr increase. The results of this research could thus help hydraulic designers to consider their selections for the optimum design of stilling basins more carefully.