scholarly journals Three-Dimensional Investigation of Hydraulic Properties of Vertical Drop in the Presence of Step and Grid Dissipators

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 895
Author(s):  
Rasoul Daneshfaraz ◽  
Ehsan Aminvash ◽  
Amir Ghaderi ◽  
Alban Kuriqi ◽  
John Abraham
Keyword(s):  
Energy Dissipation ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Relative Energy ◽  
Relative Depth ◽  
Pool Depth ◽  
Drainage Channels ◽  
Simultaneous Use ◽  
Fully Coupled ◽  
Irrigation And Drainage Channels

In irrigation and drainage channels, vertical drops are generally used to transfer water from a higher elevation to a lower level. Downstream of these structures, measures are taken to prevent the destruction of the channel bed by the flow and reduce its destructive kinetic energy. In this study, the effect of use steps and grid dissipators on hydraulic characteristics regarding flow pattern, relative downstream depth, relative pool depth, and energy dissipation of a vertical drop was investigated by numerical simulation following the symmetry law. Two relative step heights and two grid dissipator cell sizes were used. The hydraulic model describes fully coupled three-dimensional flow with axial symmetry. For the simulation, critical depths ranging from 0.24 to 0.5 were considered. Values of low relative depth obtained from the numerical results are in satisfactory agreement with the laboratory data. The simultaneous use of step and grid dissipators increases the relative energy dissipation compared to a simple vertical drop and a vertical drop equipped with steps. By using the grid dissipators and the steps downstream of the vertical drop, the relative pool depth increases. Changing the pore size of the grid dissipators does not affect the relative depth of the pool. The simultaneous use of steps and grid dissipators reduces the downstream Froude number of the vertical drop from 3.83–5.20 to 1.46–2.00.

Influence of Cartilaginous Matrix Accumulation on Viscoelastic Response of Chondrocyte/Agarose Constructs Under Dynamic Compressive and Shear Loading

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Shogo Miyata ◽  
Tetsuya Tateishi ◽  
Takashi Ushida
Keyword(s):  
Energy Dissipation ◽  
Biochemical Composition ◽  
Dynamic Compression ◽  
Three Dimensional ◽  
Shear Stiffness ◽  
Relative Energy ◽  
Shear Loading ◽  
Cartilage Defects ◽  
Sgag Content ◽  
Matrix Accumulation

A method has been developed to restore cartilage defects by culturing autologous chondrocytes to create a three dimensional tissue and then implanting the cultured tissue. In this kind of approach, it is important to characterize the dynamic mechanical behavior of the regenerated cartilaginous tissue, because these tissues need to bear various dynamic loadings in daily life. The objectives of this study were to evaluate in detail the dynamic viscoelastic responses of chondrocyte-seeded agarose gel cultures in compression and torsion (shear) and to determine the relationships between these mechanical responses and biochemical composition. The results showed that both the dynamic compressive and shear stiffness of the cultured constructs increased during culture. The relative energy dissipation in dynamic compression decreased, whereas that in dynamic shear increased during culture. Furthermore, correlation analyses showed that the sulfated glycosaminoglycan (sGAG) content of the cultured construct showed significant correlations with the dynamic modulus in both compression and shear situations. On the other hand, the loss tangent in dynamic compression, which represents the relative energy dissipation capability of the constructs, showed a low correlation with the sGAG content, whereas this capability in shear exhibited moderate correlation. In conclusion, we explored the dynamic viscoelasticity of the tissue-engineered cartilage in dynamic compression and shear, and determined correlations between viscoelasticity and biochemical composition.

scholarly journals Study of the performance of support vector machine for predicting vertical drop hydraulic parameters in the presence of dual horizontal screens

2020 ◽  
Author(s):  
Rasoul Daneshfaraz ◽  
Mohammad Bagherzadeh ◽  
Reza Esmaeeli ◽  
Reza Norouzi ◽  
John Abraham
Keyword(s):  
Support Vector Machine ◽  
Laboratory Data ◽  
Evaluation Criteria ◽  
Energy Parameter ◽  
Relative Length ◽  
Relative Energy ◽  
Support Vector ◽  
Relative Depth ◽  
Hydraulic Parameters ◽  
Testing Stage

Abstract In the present study, the performance of the support vector machine for estimating vertical drop hydraulic parameters in the presence of dual horizontal screens has been investigated. For this purpose, 120 different laboratory data were used to estimate three parameters of the drop: the relative length, the downstream relative depth, and the residual relative energy in the support vector machine. For each parameter, 12 models were analyzed by using a support vector machine. The performance of the models was evaluated with statistical criteria (R2, DC, and RMSE) and the best model was introduced for each of the parameters. The evaluation criteria for the relative length of the vertical drop equipped with dual horizontal screens for the testing stage are R2 = 0.992, DC = 0.981 and RMSE = 0.050. Also, the values of the downstream relative depth evaluation indicators for the testing stage are R2 = 0.9866, DC = 0.980 and, RMSE = 0.0064. For the residual relative energy parameter, the values of the residual relative energy evaluation indicators are R2 = 0.9949, DC = 0.9853 and RMSE = 0.0056. The results showed the capacity for this approach to predict the hydraulic performance of these systems with accuracy.

scholarly journals Flow Over Embankment Gabion Weirs in Free Flow Conditions

2021 ◽  
Author(s):  
Roya Biabani ◽  
Farzin Salmasi ◽  
Meysam Nouri ◽  
John Abraham
Keyword(s):  
Energy Dissipation ◽  
Three Dimensional ◽  
Relative Energy ◽  
Physical Models ◽  
Flow Conditions ◽  
Environmental Aspects ◽  
Discharge Coefficients ◽  
Filling Materials ◽  
Surface Profiles ◽  
Crest Length

Abstract Gabion weirs have been widely used in rivers restoration and diversion water projects because of their hydro-environmental aspects and eco-friendly features. In this study, a series of laboratory tests were performed to investigate the effects of side ramp slope, crest length, and porous media properties on the flow regimes, water-surface profiles, discharge coefficients, and energy dissipation in embankment gabion weirs with upstream and downstream slopes. 24 physical models of solid and gabion weirs with three different upstream/downstream slopes (90°, 45° and 26.5°) were created. For gabion weirs, three different filling materials were tested. To investigate the complexity of flow over the porous-fluid interface and through the porous material, three-dimensional (3D) numerical simulations were developed. The results show that decreasing upstream slopes, from 90º to 26.5º, leads to decreased discharge coefficients. However, in all cases, gabion weirs lead to greater discharge coefficients than those of similar solid weirs. For milder side slopes, discharge ratios passing through all faces of the gabion weirs decreased nonlinearly. Moreover, with increasing the inlet discharge, relative energy dissipation was reduced up to 45% in gabion weirs.

Mathematical Model Investigation of Far-Field Transport of Ocean-Dumped Sewage Sludge Related to Remote Sensing

1982 ◽  
Vol 14 (3) ◽  
pp. 33-39
Author(s):  
C Y Kuo
Keyword(s):  
New York ◽  
Sewage Sludge ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Approximate Model ◽  
Transport Processes ◽  
Far Field ◽  
New York Bight ◽  
Mean Current

An existing, three-dimensional, Eulerian-Lagrangian finite-difference model was modified and used to examine the far-field transport processes of dumped sewage sludge in the New York Bight. Both in situ and laboratory data were utilized in an attempt to approximate model inputs such as mean current speed, vertical and horizontal diffusion coefficients, particle size distributions, and specific gravities. Concentrations of the sludge near the sea surface predicted from the computer model were compared qualitatively with those remotely sensed.

RETARDATION EFFECTS IN COVARIANT THREE-DIMENSIONAL BOUND STATE WAVE FUNCTIONS

2005 ◽  
Vol 14 (06) ◽  
pp. 931-947 ◽  
Author(s):  
F. PILOTTO ◽  
M. DILLIG
Keyword(s):  
Bound States ◽  
Three Dimensional ◽  
Bound State ◽  
Relative Energy ◽  
Wave Functions ◽  
Three Dimensions ◽  
State Wave ◽  
Scalar Diquark ◽  
Bound State Wave Function ◽  
Retardation Effects

We investigate the influence of retardation effects on covariant 3-dimensional wave functions for bound hadrons. Within a quark-(scalar) diquark representation of a baryon, the four-dimensional Bethe–Salpeter equation is solved for a 1-rank separable kernel which simulates Coulombic attraction and confinement. We project the manifestly covariant bound state wave function into three dimensions upon integrating out the non-static energy dependence and compare it with solutions of three-dimensional quasi-potential equations obtained from different kinematical projections on the relative energy variable. We find that for long-range interactions, as characteristic in QCD, retardation effects in bound states are of crucial importance.

A Meso-Electro-Mechanical Model for PMN-PT-BT Ceramics Behavior

2001 ◽  
Author(s):  
Jinghong Fan
Keyword(s):  
Phase Transition ◽  
Mechanical Model ◽  
Three Dimensional ◽  
Constitutive Behavior ◽  
Rate Equations ◽  
State Variables ◽  
Empirical Relationships ◽  
Nonlinear Hysteresis ◽  
Fully Coupled ◽  
Maximum Permittivity

Abstract A three-dimensional, meso-electro-mechanical model has been formulated for description of PMN-PT-BT ceramics. Unlike the experimentally fit models and phenomenological models which are based on state variables and/or empirical relationships, this fully coupled, computational mesomechanics model for polycrystalline PMN-PT-BT ceramics is developed based on considerations of constitutive behavior of single crystals. Specifically, domain wall nucleation and evolution rate equations are proposed in this work to describe the nonlinear hysteresis behavior of these ceramics near the phase transition temperature with maximum permittivity.

Drying characteristics of oil shale under microwave heating based on a fully coupled three-dimensional electromagnetic-thermal-multiphase transport model

Fuel ◽  
2022 ◽  
Vol 308 ◽  
pp. 121942
Author(s):  
Jingyi Zhu ◽  
Xiaogang Li ◽  
Zhaozhong Yang ◽  
Jie Zhou ◽  
Hao Wang
Keyword(s):  
Microwave Heating ◽  
Oil Shale ◽  
Transport Model ◽  
Three Dimensional ◽  
Multiphase Transport ◽  
Drying Characteristics ◽  
Fully Coupled

scholarly journals NEW EVIDENCE OF DISCRETE SCALE INVARIANCE IN THE ENERGY DISSIPATION OF THREE-DIMENSIONAL TURBULENCE: CORRELATION APPROACH AND DIRECT SPECTRAL DETECTION

2003 ◽  
Vol 14 (04) ◽  
pp. 459-470 ◽  
Author(s):  
WEI-XING ZHOU ◽  
DIDIER SORNETTE ◽  
VLADILEN PISARENKO
Keyword(s):  
Energy Dissipation ◽  
Three Dimensional ◽  
Energy Dissipation Rate ◽  
Corrections To Scaling ◽  
Developed Turbulence ◽  
Pairwise Correlations ◽  
Spectral Detection ◽  
Simple Variant ◽  
High Reynolds ◽  
New Evidence

We extend the analysis of Ref. 16 showing statistically significant log-periodic corrections to scaling in the moments of the energy dissipation rate in experiments at high Reynolds number (≈ 2500) of three-dimensional fully developed turbulence. First, we develop a simple variant of the canonical averaging method using a rephasing scheme between different samples based on pairwise correlations that confirms Zhou and Sornette's previous results. The second analysis uses a simpler local spectral approach and then performs averages over many local spectra. This yields stronger evidence of the existence of underlying log-periodic undulations, with the detection of more than 20 harmonics of a fundamental logarithmic frequency f = 1.434 ± 0.007 corresponding to the preferred scaling ratio γ = 2.008 ± 0.006.

Three-Dimensional Analysis of Closed-Die Forging Processes: Part 1: Formulation

1989 ◽  
Vol 203 (1) ◽  
pp. 33-37 ◽  
Author(s):  
C F Lugora ◽  
A N Bramley
Keyword(s):  
Theoretical Model ◽  
Energy Dissipation ◽  
Metal Flow ◽  
Three Dimensional ◽  
Total Rate ◽  
Die Forging ◽  
Closed Die Forging ◽  
Proposed Model ◽  
Optimum Velocity ◽  
Forging Load

In this series of papers, a theoretical model based on the upper bound elemental technique is presented for prediction of forging load and metal flow in three-dimensional closed-die forging processes. Three basic elements are introduced in order to partition a forging into simple elementary regions. An optimum velocity distribution within the forging is obtained by minimizing the total rate of energy dissipation using a simplex optimizing procedure. Applications of the proposed model are discussed in Part 2.

Fully coupled three-dimensional nonlinear numerical simulation of pumping-induced land movement

2017 ◽  
Vol 76 (16) ◽  
Author(s):  
Yun Zhang ◽  
Jichun Wu ◽  
Yuqun Xue ◽  
Zhecheng Wang
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Nonlinear Numerical Simulation ◽  
Fully Coupled
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