A study in hydraulic performance indices for Sediment Retention Ponds

2014 ◽  
pp. 251-257 ◽  
Author(s):  
Arash Farjood ◽  
Bruce Melville ◽  
Asaad Shamseldin
Keyword(s):  
Hydraulic Performance ◽  
Performance Indices ◽  
Sediment Retention ◽  
Retention Ponds ◽  
Sediment Retention Ponds

Evaluation of hydraulic performance indices for retention ponds

2015 ◽  
Vol 72 (1) ◽  
pp. 10-21 ◽  
Author(s):  
Arash Farjood ◽  
Bruce W. Melville ◽  
Asaad Y. Shamseldin ◽  
Keith N. Adams ◽  
Sher Khan
Keyword(s):  
Hydraulic Performance ◽  
Hydraulic Efficiency ◽  
Hydraulic Analysis ◽  
Performance Indices ◽  
Sediment Retention ◽  
Retention Pond ◽  
Retention Ponds ◽  
Sediment Retention Ponds ◽  
Moment Index ◽  
Selection Of

Abstract Comprehensive hydraulic analysis of sediment retention ponds is commonly achieved through interpretation of residence time distribution and derivation of indices associated with short-circuiting and mixing. However, the availability of various indices indicates the need for careful selection of the most appropriate indices. This study compares some of the commonly used hydraulic performance indices, together with a new short-circuiting index, τ5, for five different flow regimes in a model sediment retention pond. The results show that τ5 was the best measure for short-circuiting. Among the mixing indices, only the Morril index correctly represented the physical behaviour of the experiments. In addition, two hydraulic efficiency indices, λ and a moment index (MI) were assessed and showed a good correlation with the short-circuiting and mixing indices, but MI was more reproducible than λ. Based on these results, this study recommends using τ5, Morril index and MI for analysis of hydraulic performance in sediment retention ponds.

scholarly journals Experimental investigation of the effect of temperature differentials on hydraulic performance and flow pattern of a sediment retention pond

2018 ◽  
Vol 77 (12) ◽  
pp. 2896-2906 ◽  
Author(s):  
Ehsan Hendi ◽  
Asaad Y. Shamseldin ◽  
Bruce W. Melville ◽  
Stuart E. Norris
Keyword(s):  
Residence Time ◽  
Hydraulic Performance ◽  
Effect Of Temperature ◽  
Sediment Retention ◽  
Small Temperature ◽  
Thermally Induced ◽  
Retention Pond ◽  
Retention Ponds ◽  
Sediment Retention Ponds ◽  
Counter Current

Abstract Existing studies on sediment retention ponds (SRPs) have examined the effects of pond layout, inlet and outlet geometry and the installation of baffles on the performance of the SRPs. However, the effects of a temperature difference between the ambient water in the pond and the inflow are often neglected, and the buoyancy forces arising from these differences in temperature can potentially change the flow in the pond and hence its hydraulic performance. This study has experimentally evaluated the effect of these temperature differences on the flow field and residence time in a retention pond for a range of temperature differences. As expected a cold inflow sinks to the bottom of the pond while a hot inflow remains at the surface, but in both cases the inflow flows more rapidly towards the outlet than is the case for isothermal inflow. A counter-current was observed at the bottom or the surface of the pond for colder or hotter influents, respectively. These thermally induced flows significantly reduced the residence time of the pond, reducing the hydraulic performance of the pond and causing severe short-circuiting. The results have also shown that the temperature differences in the pond decrease with time, yet small temperature differences persist with the pond remaining thermally stratified.

scholarly journals Effect of baffles on the hydraulic performance of sediment retention ponds

2016 ◽  
Vol 75 (9) ◽  
pp. 1991-1996
Author(s):  
Sher Khan ◽  
Bruce W. Melville ◽  
Mudasser Muneer Khan ◽  
Muhammad Shoaib ◽  
Asaad Shamseldin
Keyword(s):  
Physical Model ◽  
Residence Time ◽  
Hydraulic Performance ◽  
Large Area ◽  
Sediment Retention ◽  
Retention Pond ◽  
Retention Ponds ◽  
Sediment Retention Ponds

An investigation of the effect of baffles on retention pond performance using a physical model of an existing sediment retention pond is presented. Analysis of residence time (RTD curves) was used to compare the hydraulic performance of different arrangements of baffles in the pond. Five different arrangements for the design of baffles were studied. The results show that placing a single baffle to deflect the influent to a sediment retention pond does not improve pond performance; rather, it stimulates short-circuiting. This is contradictory to the literature and is considered to be a consequence of the model pond incorporating sloping walls, which is a novel aspect of this study. Most of the previous studies have neglected the effects of battered walls. Conversely, the inclusion of more than two baffles was found to increase the hydraulic performance. The results reported here are limited to small and narrow ponds where a large portion of the pond is batter (i.e. made up of sloping walls). For large area ponds, batter effects may be negligible and are likely to be different from those reported here.

The effect of different baffles on hydraulic performance of a sediment retention pond

2015 ◽  
Vol 81 ◽  
pp. 228-232 ◽  
Author(s):  
Arash Farjood ◽  
Bruce W. Melville ◽  
Asaad Y. Shamseldin
Keyword(s):  
Hydraulic Performance ◽  
Sediment Retention ◽  
Retention Pond

scholarly journals Hydraulic investigation of the impact of retrofitting floating treatment wetlands in retention ponds

2019 ◽  
Vol 80 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Sher Khan ◽  
Muhammad Shoaib ◽  
Mudasser Muneer Khan ◽  
Bruce W. Melville ◽  
Asaad Y. Shamseldin
Keyword(s):  
Root Length ◽  
Longitudinal Axis ◽  
Hydraulic Performance ◽  
Treatment Wetlands ◽  
Experimental Investigations ◽  
Retention Pond ◽  
Retention Ponds ◽  
Floating Treatment Wetlands ◽  
The Impact ◽  
Stormwater Retention

Abstract This paper describes the laboratory experimental investigations undertaken to analyse the influence of floating treatment wetlands (FTWs) on the hydraulic performance of a stormwater retention pond. Two experimental series were conducted, each focussed on investigating the influence of placing an FTW in a pond with firstly the inflow entering the retention pond from an inlet positioned 0.25 m offset from the longitudinal axis of the pond, and secondly the inlet positioned at the longitudinal axis of the pond. For both series of experiments, tests were undertaken at 1 l/s and 1.5 l/s, and with and without an artificial FTW installed. This study is the first to investigate the hydraulic impact of FTWs and their root systems on the performance of stormwater retention ponds. The results presented in this study suggest that FTWs are a viable method to minimise hydraulic inefficiencies, thereby increasing retention time and optimising hydraulic performance of stormwater retention ponds. The results highlight the importance of plant root characteristics. The optimal arrangement of root length is LR/DP = 0.5, where LR = root length and DP = pond depth. The results also indicate that the spatial variability of vegetation has a significant impact on the hydraulic performance of the pond.

RELAÇÃO VAZÃO x PRESSÃO EM MICROASPERSORES DAN 2001 SOB CONDIÇÃO ADVERSA DE OPERAÇÃO

Irriga ◽  
2003 ◽  
Vol 8 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Marco Antonio Fonseca Conceição ◽  
Rubens Duarte Coelho
Keyword(s):  
Hydraulic Performance ◽  
Sao Paulo ◽  
The Self ◽  
São Paulo ◽  
Flow Curves ◽  
Pressure Flow ◽  
Adverse Condition ◽  
Irrigation Time ◽  
E Mail ◽  
Stable Flow

RELAÇÃO VAZÃO x PRESSÃO EM MICROASPERSORES DAN 2001 SOB CONDIÇÃO ADVERSA DE OPERAÇÃO  Marco Antônio Fonseca ConceiçãoEmbrapa Uva e Vinho, Estação Experimental de Jales, Jales, SP. CP 241. CEP 15700-000.E-mail: [email protected] Duarte CoelhoDepartamento de Engenharia Rural, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, SP. CP 09, CEP 13418-900.E-mail: [email protected]  1 RESUMO  Alguns microaspersores possuem membranas que regulam a sua pressão de operação, mantendo a vazão praticamente estável dentro de uma faixa de pressão na rede hidráulica. Operadores de irrigação no campo, muitas vezes com baixo nível de instrução e sem orientação profissional qualificada, visando reduzir problemas de entupimento ou para diminuir o tempo de irrigação, costumam retirar as membranas autocompensantes para aumentar a vazão do emissores, o que pode comprometer o desempenho hidráulico do sistema. Para avaliar o efeito da retirada da membrana  sobre as vazões dos microaspersores, no presente trabalho determinou-se as relações entre pressão e vazão para sete bocais do microaspersor DAN 2001, operando na ausência da membrana autocompensante. As curvas pressão-vazão sem as membranas autocompensantes apresentaram comportamento potencial com expoentes variando entre 0,58 e 0,64. As vazões dos microaspersores sem as membranas aumentaram de forma inversamente proporcional aos diâmetros dos emissores, quando comparadas às vazões nominais com as membranas.  UNITERMOS: Hidráulica, irrigação, microaspersão.  CONCEIÇÃO, M.A.F.; COELHO, R.D. FLOW X PRESSURE RELATIONSHIP FOR DAN 2001 MICROSPRINKLERS UNDER ADVERSE CONDITION  2 ABSTRACT  Many types of microsprinklers have a self-compensating membrane to regulate their pressure, keeping a stable flow. Many producers usually take the membranes off to reduce clogging problems  or irrigation time. This procedure could endanger the system hydraulic performance. To evaluate the effect of taking off the self-compensating membrane from microsprinklers it was determined, in the present work, the pressure-flow relationship for seven Dan 2001 microsprinkler nozzles operating without the membrane. The pressure-flow curves presented a potential behavior with the exponents varying from 0.58 to 0.64. Microsprinkler flows without the membranes increased inversely proportional to the emitter diameters, comparing to the nominal flows using the membranes.  KEYWORDS: Hydraulic, irrigation, microsprinkler.

Sign in / Sign up

Export Citation Format

Share Document