No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Superiority of the computer-based approach in solving iterative open channel hydraulic problems
Abstract
The study of engineering lays more of a focus on mathematics and analytical thinking than other academic subjects. One of the outputs required for the accreditation of programs providing this education is to train engineers who have the ability to define, formulate/solve complex engineering problems, design under realistic constraints and conditions, and select/apply appropriate analysis/modeling methods for this purpose. In particular, fluid mechanics (a discipline that focuses on the study of fluids (liquids and gases) and the forces acting on them) and hydraulics (a subfield of hydrodynamics concerned with liquid flows in pipelines and open channels) courses, which are compulsory in the environmental and civil engineering curriculum, are considered to be the basic courses of scientific/technical education. These courses play a key role in providing the basic qualifications required to meet discipline-specific criteria in the accreditation of engineering undergraduate programs. In hydraulic engineering, the design of structures related to pressurized pipe flows and open channel flows (free surface flows) requires realistic and appropriate physical and mathematical modeling studies. In this regard, much faster and more precise results can be obtained compared to conventional methods by using effective programming languages in solving complex problems modeled with mathematical expressions. This study aimed to boost the incentive for computer-based technique in basic engineering education and to highlight its significance in solving four iterative open channel hydraulic problems. The MATLAB® software was used to create computer-based solutions, and pertinent illustrations and coding information were provided in-depth for engineers, educators, and students. Moreover, student performances on midterm tests administered over the course of two consecutive semesters was evaluated in relation to manual problem solutions, and the challenges related to the traditional approach were examined within the scope of this study.
ResearchGate has not been able to resolve any citations for this publication.
This study is dedicated to the examination of cavitation-induced erosion, a critical factor in optimizing the efficiency of hydraulic systems, including hydropower plants and pumping systems. To accomplish this, we conducted a sensitivity analysis utilizing a cavitation jet apparatus (CJA) and an experimental configuration that featured a vertical cylindrical test tank, a submerged nozzle, and an aluminum sample (specifically, alloy 6351 T6). The study maintained a consistent standoff distance of 5 cm and an orifice diameter of 2 × 10-3 m. Two distinct nozzle geometries were tested to assess their influence on cavitation erosion. The outcomes revealed that the 20° conical sharped-edges nozzle resulted in the highest erosion rates, while the commercial nozzle (MEG 2510) caused comparatively less erosion. By standardizing the test duration to 1200 seconds and using a cavitation index of 0.14, the researchers avoided overlapping pits. In summary, the CJA, with these adjustments, demonstrated its effectiveness as a tool for evaluating the resistance of solid surfaces to cavitation.
This article demonstrates the successful application of Long Short-Term Memory (LSTM) recurrent neural networks to simulate streamflow in the Aquidauana River basin, located in the Brazilian Pantanal. The LSTM network used daily precipitation data as input to predict future streamflow in the region. The results obtained from this research show a coefficient of determination (R2) of 0.82, indicating a strong fit of the model to the observed data. Additionally, the Root Mean Squared Error (RMSE) was found to be 0.53, indicating the model's accuracy in predicting streamflow compared to actual data. These findings highlight the effectiveness of LSTM networks in hydrological modeling for the Pantanal region, which is crucial for water resource planning and sustainable management in this ecologically significant area. This study is expected to serve as a catalyst for further research and make a substantial contribution to the advancement of streamflow prediction techniques in complex watersheds such as the Aquidauana River basin.
This study provides novel and accurate symbolic regression-based solutions for the calculation of pipe diameter when flow rate and pressure drop (head loss) are known, together with the length of the pipe, absolute inner roughness of the pipe, and kinematic viscosity of the fluid. PySR and Eureqa, free and open-source symbolic regression tools, are used for discovering simple and accurate approximate formulas. Three approaches are used: (1) brute force of computing power, which provides results based on raw input data; (2) an improved method where input parameters are transformed through the Lambert W-function; (3) a method where the results are based on inputs and the Colebrook equation transformed through new suitable dimensionless groups. The discovered models were simplified by the WolframAlpha simplify tool and/or the equivalent Matlab Symbolic toolbox. Novel models make iterative calculus redundant; they are simple for computer coding while the relative error remains lower compared with the solution through nomograms. The symbolic-regression solutions discovered by brute force computing power discard the kinematic viscosity of the fluid as an input parameter, implying that it has the least influence.
This paper deals with results of a systemized overview of the Chézy roughness coefficient calculation problem as one most frequently used empirical characteristics of hydraulic resistance. The overview is given in the context of the formation of reliable empirical data needed to support hydro-engineering calculations and mathematical modelling of open flows in river channels. The problem topicality is because of a large number of practical tasks which need such a pre-research. In many cases, the accuracy of determining empirical hydraulic resistance characteristics can largely affect the accuracy of solving tasks relating to designing hydraulic structures and water management regardless of chosen mathematical models and methods.Rivers are characterized by a significant variety of flow conditions; hydraulic resistance to flows in rivers can thus vary widely determining their flow capacity. Considering the variety of river hydro-morphology and hydrology, the Chézy roughness coefficient often appears to be the most complete characteristic of hydraulic resistance to open flows in river channels comparing with other integral empirical characteristics of hydraulic resistance.At present, there are a large number of empirical and semi-empirical formulas to calculate the Chézy roughness coefficient. The main aim of this study was to analyze and systematize them in the context of providing proper support to the open channel hydraulics tasks. To achieve the aim of the study, a literature review regarding the problem of determining the integral hydraulic resistance characteristics to open flow in river channels was performed, as well as formulas used to calculate the Chézy roughness coefficient in practice were explored and systemized. In total, 43 formulas to calculate the Chézy roughness coefficient, as well as 13 formulas that can be used to estimate the Manning roughness coefficient were analyzed and systematized. Based on all these formulas, about 250 empirical equations can be compiled to calculate the Chézy coefficient depending on hydro-morphological peculiarities of rivers and river channels, hydraulic conditions, formulas application limits, and so on.
Computational thinking (CT) is one of the skills or processes needed in computer science. However, these skills can also be integrated into any field in education. The objective of this literature review is to study the benefits and challenges of computational thinking (CT) in education. This literature review is analyses 55 references obtained from various sources, based on predefined keywords. The references were then analysed using NVivo software to code them according to several main points. Based on the literature review, there are many benefits of computational thinking in education, including increasing critical and analytical thinking among students, cultivating CT skills in STEM education among students, improving pedagogy and curriculum, and fostering CT skills through game-based learning (GBL). However, there are some challenges facing the implementation of computational thinking in the field of education. These include teachers’ understanding of computational CT, lack of confidence, lack of the skills required to implement CT, and students’ acceptance of CT. In order to overcome these challenges, there are two important aspects to consider: ensuring teachers’ level of knowledge and level of readiness about CT is high. It is hoped that this literature review will be able to provide educators with an understanding of the extent to which CT is able to shape education to be more creative and meaningful.
Subjects related to fluid mechanics for hydraulic engineers ought to be delivered in interesting and active modes. New methods should be introduced to improve the learning students’ abilities in the different courses of the Bachelor’s and Master’s degree. Related to active learning methods, a continuous project-based learning experience is described in this research. This manuscript shows the developed learning methodology, which was included on different levels at Universitat Politècnica de València. The main research goal is to show the active learning methods used to evaluate both skills competences (e.g., “Design and Project”) and specific competences of the students. The research shows a particular developed innovation teaching project, which was developed by lecturers and professors of the Hydraulic Engineering Department, since 2016. This project proposed coordination in different subjects that were taught in different courses of the Bachelor’s and Master’s degrees, in which 2200 students participated. This coordination improved the acquisition of the learning results, as well as the new teaching methods increased the student’s satisfaction index.
Estimating the value of discharge in water ways is an important factor in the flood controlling projects. Recently by advances in flood management, investigators have proposed to use the concept of compound section for modeling the flow characteristics in the natural waterways such as rivers. Several conceptual and theoretical approaches based on the idea of compound section have been proposed for estimating the discharge in rivers. In this study, the performances of the theoretical methods were assessed using performing series of experiments in straight prismatic compound open channel and also analyzing the published data in the literature. Analyzing the performance of theoretical methods shows that Divided Channel Method including vertical bounded line with the determination of coefficient (0.91) and root mean square error (0.02) is an accurate method through the theoretical approaches and only this method has suitable ability to apply for practical purposes.
In complex carbonate reservoirs, it is crucial to understand the connections between reservoir compositions (minerals, facies, and properties). Conventionally, core samples have been used to measure reservoir parameters and identify minerals and facies. However, core samples are limited to certain wells. Therefore, additional techniques are necessary to overcome this limitation comprehensively. This study aims to identify key mineralogical and facies components of the Barra Velha Formation (BVF) and their relation to reservoir parameters. Dolomite, calcite, quartz, and clay minerals were commonly found using X-Ray Diffraction (XRD). By employing multi-mineral (MM) petrophysical evaluations, we accurately recreated mineral quantities from XRD and petrophysical properties from core analysis to ensure reliability. Replications of inputs well logs and the mineralogical volume from spectroscopic (ECS) were used as reliability techniques for validating the MM. A total of 47 wells were analyzed using those methods. In this study, the classification of facies was accomplished through the selection of three prominent supervised artificial intelligence techniques, among which SOM, a widely employed method for facies estimation, was included. Additionally, the ensemble methods of Random Forest and XGBoost were adopted due to their recognized efficacy in handling tabular data and their track record of success in machine learning and artificial intelligence competitions. Remarkably, the performance evaluation revealed that Random Forest and XGBoost algorithms outperformed SOM, yielding the most favorable outcomes in this context. An integrated analysis of mineralogical and facies results was conducted, incorporating production data and special profiles such as nuclear magnetic resonance (NMR) and Wellbore Image (WBI) to identify vug-containing areas. The dolomitic facies exhibited favorable reservoir qualities, influenced by diagenetic processes represented by vuggy porosity, which enhanced permeability. Shrubstones, spherulites, and reworked facies showed superior petrophysical qualities and were connected with productive regions, leading to elevated dolomite concentrations, and vuggy abundance. The study highlights two major innovations: the use of mineralogical volume from multi-mineral assessments as inputs for AI-based property estimation to improve facies estimates, and the discovery of relationships between facies, minerals, and reservoir properties, compared to production data. This understanding allows for more accurate static model creation, optimal production interval selection, improved hydrocarbon recovery, and better specification of stimulation processes.
Solutions for the three main problems in sizing of pipes that usually occurs in engineering practice are given: 1. head loss Δh, 2. flow discharge Q, and 3. diameter D. In turbulent flow, iterative calculus can be easily avoided only in solution of flow discharge Q, while head loss Δh and diameter D can be only calculated through various approximate but accurate non-iterative procedures. This article describes relevant solutions for the observed problems and compares them in numerical examples.
A network model is implemented to study the transition of flow in porous media. In this way, a real porous medium is simulated according to an orthogonal pipe network which was formed by some spheres that are connected to each other using a set of pipes. In this model the pipes play the role of existing ducts in porous medium, and the nodes (spheres) indicate existing holes in the place of duct junctions. The effects of variety in some hydraulic parameters are investigated in this model. Afterward, this network is analyzed by the combined pressurized-free surface network (CPFNET) method. The CPFNET model results were similar overall to the observed experimental data. Moreover, sensitive analyses were used based on several parameters. Due to all of them, the accuracy of this method is specified.
The wide spread of obtainable, personal computers has opened doors to vast computational capabilities which enforced educational systems especially engineering programs to develop proficiency in using computers along with experiments and theories. Teaching techniques have changed accordingly, and appropriate methods were required. An example of that development was shown in the course of Hydraulics given to Environmental Engineering undergraduate students. Students in the past spent much time on the iterative solving method used in hydraulic problems and expended a lot of energy to find the solutions. Today instead, a commonly known program called MATLAB has proven efficiency and brought great easiness which not only assisted engineers in their work but also allowed them to drive more attention on reasoning and interpretation. In this regard, three examples of hydraulic problems related to determining the minimum diameter of a pipe, the depth of uniform flow in an open channel, and the hydraulic load over a sharp-crested weir are explained with fully executable MATLAB codes for the solution. This study requires basic understanding of Hydraulics and familiarity with MATLAB. It benefits any branch of engineering concerned with hydraulics.
In addition to teaching undergraduate technical majors about theory and experiments, an important component of their instruction should be to develop proficiency in using computers for simulations and data presentation. A particularly appropriate course for this purpose is classical mechanics because one of the primary goals of that course is to simulate the motion of physical systems, which is greatly aided by visualizations that help to build students’ intuition about expected behaviors. As a demonstration of the ease with which this objective can be accomplished using the MATLAB software package, fully executable scripts are presented here for three commonly studied systems: point projectiles, simple pendula, and water flowing out of a hole in a tank. It is much easier for students to edit a functioning script than to try to write their own from scratch. However, the present scripts are sufficiently short and well-documented that instructors can readily ask their students to modify and adapt them according to their local instructional environments and purposes.
Computational Thinking represents a terminology that embraces the complex set of reasoning processes that are held for problem stating and solving through a computational tool. The ability of systematizing problems and solve them by these means is currently being considered a skill to be developed by all students, together with Language, Mathematics and Sciences. Considering that Computer Science has many of its roots on Mathematics, it is reasonable to ponder if and how Mathematics learning can be influenced by offering activities related to Computational Thinking to students. In this sense, this article presents a Systematic Literature Review on reported evidences of Mathematics learning in activities aimed at developing Computational Thinking skills. Forty-two articles which presented didactic activities together with an experimental design to evaluate learning outcomes published from 2006 to 2017 were analyzed. The majority of identified activities used a software tool or hardware device for their development. In these papers, a wide variety of mathematical topics has been being developed, with some emphasis on Planar Geometry and Algebra. Conversion of models and solutions between different semiotic representations is a high level cognitive skill that is most frequently associated to educational outcomes. This review indicated that more recent articles present a higher level of rigor in methodological procedures to assess learning effects. However, joint analysis of evidences from more than one data source is still not frequently used as a validation procedure.
A novel educational methodology, Implementation of Mathematical, Experimental, and Computer-based Education (IMECE), where its name was derived from the letters of the word “imece” (a Turkish tradition) by taking into account the integrative meaning of this cultural concept, was proposed to explore the synergistic effect of the conventional mathematical solution procedure, visual application, and MATLAB-based simulation on the perceptions and learning quality of the engineering students. Within the scope the present research carried out both at the state university (undergraduate and graduate levels) and at the foundation university (undergraduate level), water discharge problem (a special case of the Bernoulli's principle/Toricelli's law) was chosen as an example application. In the study, the experimental results of three different tank models (vertical cylindrical, conical, and spherical) and the solution algorithms written in MATLAB were presented in detail, and new empirical equations were also developed for each laboratory scale system depending on the experimental data. The effectiveness of the proposed IMECE method was evaluated statistically within the framework of both “Student Survey” and “Student Assessment” conducted with the participation of 84 students. Based on the mean scores obtained for all participating students, the results of the statistical tests indicated that the quantitative performance (or effectiveness) of the applied IMECE methodology was determined as 97.73%, 67.36%, and 82.55% for the perception/satisfaction section, the learning section, and the overall evaluation category, respectively.
This paper studies flow resistance characteristics of corrugated circular drainage pipes through experimental measurements and numerical calculations under turbulent uniform open-channel flow conditions. The Manning roughness coefficient n is determined for corrugated pipes where semicircular ribs are placed on the inner surface of the pipe periodically with different height-to-pitch ratios. Numerical simulations are conducted for circular pipes having diameters of 0.6, 0.8, 1.2, 1.6, and 2.2 m and a slope of 7% with discharges varying between 0.1 and 2.5 m³/s. Results of the numerical calculations are validated in terms of Manning's n by full-scale experiments. In this way, experiments are conducted for smooth and corrugated pipes of 0.8 m diameter, where two distinct inner corrugation profiles and various flow rates are employed. It is found that the Manning roughness coefficient can be increased significantly, which is a favorable outcome with regard to reducing the abrasive effect of water by lowering its velocity to more plausible values for steep slopes in an underground pipe network. Considering the numerical results, a new correlation between Manning's n and the height-to-pitch ratio of corrugation is proposed.
To meet the urgent need for a well-prepared CS&E workforce, we must better understand how students perceive the field.
A systematics literature review of computational thinking in mathematics education: Benefits and challenges
- R Isharyadi
- D Juandi
- Isharyadi
Teachers views' and student qualifications for the basic programming course in vocational high schools
- P Arslan
Arslan P. Teachers views' and student qualifications for the basic
programming course in vocational high schools. M.Sc. Thesis, Institute
of Educational Sciences. Mersin University; Turkey: 2019.
Hydraulics of open channel flow: An introduction, Basic principles, sediment motion, hydraulic modelling, design of hydraulic structures
- H Chanson
Chanson H. Hydraulics of open channel flow: An introduction, Basic
principles, sediment motion, hydraulic modelling, design of hydraulic
structures. Burlington, MA. Elsevier Butterworth-Heinemann. 2004.
- D Apsley
Apsley D. Lecture Notes, Hydraulics 3, OCF Basics, Department
of Mechanical, Aerospace and Civil Engineering. The University of
Manchester; Manchester, U:. 2023.
A systematics literature review of computational thinking in mathematics education: Benefits and challenges. Formatif: Jurnal Ilmiah Pendidikan MIPA
- R Isharyadi
- D Juandi
Isharyadi R, Juandi, D. A systematics literature review of computational
thinking in mathematics education: Benefits and challenges. Formatif:
Jurnal Ilmiah Pendidikan MIPA. 2023;13(1):69-80.