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Papers by younes aminpour

International Journal of Civil Engineering, Jun 1, 2017

Local scour downstream of hydraulic structures is one of the critical phenomena, which has absorb... more Local scour downstream of hydraulic structures is one of the critical phenomena, which has absorbed a vast amount of interests by researchers. The designers of hydraulic structures, particularly, spillways try to utilize proper means to minimize the consequences of excess energies downstream of such structures which usually tend to erode their immediate downstream reaches. The stepped spillway is designed to create a large amount of energy losses by action of its steps to lessen the amount of scour evolution at its immediate downstream. This article presents the results of 67 experiments conducted at two different scales of stepped spillways, to study the local scour downstream of the structure. The experiments were planned to consider a wide range of geometrical factors, flow characteristics, and sediment properties. The time duration of experiments was ranged from 6 to 24 h which produced more than 80000 data points for analytical considerations. The results were used to render some regression equations to define the similarity among the scour hole profile and its geometrical characteristics. It was observed that a long-term observation would be required to reach the equilibrium state. However, semi-equilibrium conditions will be achieved some times after 24 h. It was also noted that the depth of scour hole adjacent to channel walls was bigger than that of centerline. Finally, it was realized that the stepped spillway causes energy dissipation between 42.06 and 74.82% which results in a shallower scour hole compared to ogee spillways.

Irrigation and Drainage

Drip irrigation is the most suitable system for reusing effluents in agriculture, but emitter clo... more Drip irrigation is the most suitable system for reusing effluents in agriculture, but emitter clogging is still its major drawback. Adequate filtration is needed to prevent emitter clogging, but little information is available about the performance of different filter types when using fish farm effluent. The purpose of this study was to evaluate the performance of three filtration treatments for rainbow trout effluent in drip irrigation systems: (1) sand filter (T1), (2) sand filter followed by a disc filter (T2) and (3) sand filter followed by a screen filter (T3). The treatments were tested with a constant discharge of 14.4 m3 h−1 at two working pressures of 300 and 150 kPa until reaching the backwashing threshold. For each filter, the following were computed: filtered volume per cross‐section until reaching the backwashing threshold (VB), filtered volume per cross‐section unit and head loss (V10), suspended solids removal efficiency (EF) and filter mass retention (q). T2 at 300 k...

Water Resources Management

Journal of Irrigation and Drainage Engineering, 2021

Journal of Irrigation and Drainage Engineering, 2020

Progress in Agricultural Engineering Sciences, 2018

An accurate estimation of losses created by wind drift and evaporation is necessary for water man... more An accurate estimation of losses created by wind drift and evaporation is necessary for water management in sprinkler irrigation systems. In the current study, three artificial intelligence (AI) methods, namely artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS) and gene expression programming (GEP), were used to estimate the wind drift and evaporation losses (WDEL) based on influential variables such as operating pressure (P), wind speed (W), nozzle diameter (D) and vapour pressure deficit (e s À e a). Field measurements data were applied to training and testing of ANN, ANFIS and GEP models. The results of these AI models were also compared with previous studies. Three statistical metrics, namely coefficient of determination (R 2), root mean square error (RMSE) and mean absolute error (MAE), were utilized to assess the performance of the models. The results indicate that the AI models (i.e. ANFIS, ANN and GEP) predict the WDEL more accurately than in previous studies. Moreover, the results show that the GEP model (with RMSE = 1.19% and R 2 = 0.97) provides a better estimation of WDEL compared to the ANN model (with RMSE = 2.56% and R 2 = 0.87) and ANFIS model (with RMSE = 1.64% and R 2 = 0.94).

Applied Sciences

Floods control equipment in large dams is one of the most important requirements in hydraulic str... more Floods control equipment in large dams is one of the most important requirements in hydraulic structures. Howell–Bunger valves and butterfly valves are two of these types of flow controls that are commonly used in bottom outlet dams. The optimal longitudinal distance (L) between the two Howell–Bunger and butterfly valves is such that the turbulence of the outlet flow from the butterfly valve should be dissipated before entering the outlet valve. Subsequently, the flow passing through the butterfly valves must have a fully developed flow state before reaching the Howell–Bunger valve. Therefore, the purpose of this study was to evaluate the optimal longitudinal distance between the Howell–Bunger and butterfly valves. For this purpose, different longitudinal distances were investigated using the Flow-3D numerical model. The ideal longitudinal distance obtained from the numerical model in the physical model was considered and tested. Based on the numerical study, the parameters of flow ...

Agricultural Water Management

This study aims to investigate the performance of disc, conventional screen, and automatic screen... more This study aims to investigate the performance of disc, conventional screen, and automatic screen filters when rainbow trout fish effluent is used for irrigation. The experiments were performed in a fish farm, located in the north-west of Iran. The disc and conventional screen filters were tested at pressures of 150 and 300 kPa, and the automatic screen filter at 200 and 300 kPa. The filtration experiments continued until the backwashing was reached. The results showed that (1) the initial head loss of disc and conventional screen filters was 40 kPa, while for the automatic screen filter was 5 kPa. (2) In the disc filter, with increasing working pressure, the filtered volume significantly (P<0.05) increased from 9.7 to 14.5 m3 m-2 (10 kPa)-1, but for conventional and automatic screen filters, it was constant at 5.5 and 7.0 m3 m-2 (10 kPa)-1, respectively, and all of them had significant (P<0.05) differences. (3) In the disc filter, with increasing the working pressure, the fil...

Irrigation Science, 2020

One of the most fertilizing effluents for irrigation are those from fish farms. In drip irrigatio... more One of the most fertilizing effluents for irrigation are those from fish farms. In drip irrigation systems, emitter clogging is the biggest problem of the effluent application. Therefore, the aim of this paper was to assess the clogging rate of a drip irrigation system using the effluent of a rainbow trout farm. A control treatment with the input fish farm freshwater and two more using fish farm effluent, with and without irrigation lateral drainage, were tested. Pressure compensating emitters Microflapper with nominal discharges of 4 and 8 L/h (M4, M8) and Netafim with discharges of 4, 8, and 12 L/h (N4, N8, and N12) were used. For each treatment, 42 irrigations events were carried out with a total of 336 h over a 4-month period. Each irrigation event lasted 8 h every 3 days. Clogging rate, Christiansen uniformity (CU) and emission uniformity (EU) coefficients were utilized for assessing the hydraulic performance of emitters. There was no emitter completely clogged during the experiment. However, as the clogging rate gradually increased, lateral discharges during the irrigation season decreased to a maximum of 57% of the initial value in some laterals. Evolution of the clogging rate was unstable, especially in the control treatment. N4 emitter show the best performance regardless of the quality of irrigation water. The clogging rates of M4 and N8 emitters were significantly (p < 0.05) higher when effluent was used. The N12 and M8 emitters had the highest sensitivity to clogging, without differences between treatments. Results show the dependence of clogging rate on emitter type and its discharge. The CU as well as EU for all emitters and treatments were higher than the allowable minimum. Lateral drainage had the greatest impact on the N12 and M8 emitters, which had the highest discharge. Moreover, some relationships between CU and clogging rate were obtained. It is generally possible to use the rainbow trout effluent in a drip irrigation system with pressure compensating emitters.

Hydro Science & Marine Engineering, 2020

In the present study, the flow over the stepped spillway was ‎ numerically investigated by using ... more In the present study, the flow over the stepped spillway was ‎ numerically investigated by using Flow3D model. The effect of step angle on different properties of Nappe flow regime such as the water surface profile, location of free-surface‎ aeration inception, Froude number at the ‎spillway’s toe, and pressure, flow velocity, air concentration and cavitation index were evaluated. The realizable k–ε was applied as the turbulence ‎model, and Volume of Fluid (VOF) model was used to determine the free surface flow profiles of the spillway. ‎The model was verified using experimental data. In order to investigate the different ‎characteristics of Nappe flow regime, 17 numerical runs was designed, in which, ‎four step angles, four flow discharge were considered to investigate the flow characteristics over the stepped spillway. The results indicated that the numerical model is well suited with the experimental data over the stepped spillway (RMSE = 0.147 and ARE = 6.9%). In addition, with ...

Irrigation Science, 2019

The main aim of this study was to investigate the qualitative changes of the rainbow trout efflue... more The main aim of this study was to investigate the qualitative changes of the rainbow trout effluent as water supply in a drip irrigation system. Two drip irrigation systems with a hydro-cyclone filter, sand filter and screen filter for using freshwater (control treatment) and fish farm effluent were tested in Kurdistan province (northwest of Iran) in 2017. In addition, the effect of lateral drainage at the end of each irrigation event was also studied. Two emitter types with different discharge flows were used for each treatment. In the 16 irrigation events carried out, samples were collected from the different water sources (dam, well, and river), filter outlets and lateral locations for measuring total suspended solids (TSS), particle size, pH, electrical conductivity, different compounds (Fe, Na, K, Ca, Mg, NO 3 , PO 4 , HCO 3) and the number of coliform bacteria. The results showed changes in the TSS and the number of coliform bacteria, but the remaining parameters had slight changes. In both control and effluent treatments, the filtration system significantly reduced TSS, having the screen filters the greatest effect on this decrease and hydro-cyclone and sand filter the least. To achieve higher removals, it is recommended to use finer grains in sand filters. The filtration of both control and effluent treatments increased the number of bacteria. The highest number of bacteria in the control treatment was measured after the sand filter and in the effluent treatments after the screen filter.

International Journal of Civil Engineering, 2017

Scientia Iranica, 2017

Stepped spillways are employed to reduce excess energy encountered with exiting ow from high hydr... more Stepped spillways are employed to reduce excess energy encountered with exiting ow from high hydraulic structures. Study of local scour evolution downstream of stepped spillways wilt, therefore, provide the required information to reap the bene ts made from these structures to minimize the scour hole dimensions. This paper provides the results of 67 experiments downstream of some stepped spillways subjected to di erent Froude numbers, basin lengths, tail-water depths, sediment sizes, and two di erent sloped spillways. The experiments were continued for 6, 8, 12, and 24 hours from which 824 pro les and 85000 data points were recorded and analyzed. The results show that, in certain circumstances, the dimensions of scour hole increase in accordance with particle Froude number. It was also observed that an increase in the slope of spillway would result in reduction in the geometries of scour hole. Under certain conditions, as the tail-water increases, the depth of scour hole increases and elongates the hole. The relations of duration of scour evolution downstream of stepped spillway are presented in this paper. Finally, it was observed that the stepped spillway would considerably decrease the dimensions of scour hole compared with ogee spillways, re ecting the excess energy downstream loss of stepped spillway.

Journal of Irrigation and Drainage Engineering, 2017

The development of an enhanced approach for the use of radial gates as flow measurement structure... more The development of an enhanced approach for the use of radial gates as flow measurement structures is important in irrigation networks. In this study, new theoretical relationships were developed to estimate the discharge coefficient (Cd) for a single radial gate with three different sills, at free and submerged flow conditions. These equations were calibrated and verified by using about 2600 laboratory data from the world-wide literature. Results indicated that the flow rate under the radial gates can be estimated by an error in the order of ±5%. The reliability of the proposed relationships and in particular the scale effects, were tested using 530 field data of radial gates operating on different canal networks. The predictions of the flow rates from the proposed method are shown to be superior compare with the other predictive methods. In the presence of multi radial gates in a given cross section, the total discharge is estimated by an error up to ±30% when using single radial ...

Flow Measurement and Instrumentation, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Periodica Polytechnica Civil Engineering

In this study, the hydraulic jumps over rough beds are numerically simulated. In order to calibra... more In this study, the hydraulic jumps over rough beds are numerically simulated. In order to calibrate the numerical model, the experimental data were used, which performed in a rectangular flume in various roughness arrangements and different Froude numbers. The effect of the distance (s) and the height (t) of the roughness on different characteristics of the hydraulic jump, including the sequent depth ratio, water surface profile, jump’s length, roller’s length, and velocity distribution were evaluated and compared. The results showed that the numerical model is fairly well able to simulate the hydraulic jump characteristics. The results also showed that the height and distance of roughness slightly reduced the sequent depth ratios for all Froude numbers. Also, the hydraulic jump length is reduced at the presence of the rough bed. Velocity profiles in different experiments were similar and there was a good agreement between simulated and measured results. Also, increasing the distanc...