An experimental study on the development and verification of three-dimensional tractive force measuring device using loT-based arduino

다국어 초록 (Multilingual Abstract)

When the flow in a stream goes any further, it starts to sweep small sand particles of the material form the river bed or the bank, and tractive force is defined as the ability to make sand particles to move, i.e. the shear stress acting on the bottom boundary. Evaluation of tractive force is essential for prevention of damage or erosion on river bed and embankment during a flood and efficient maintenance of rivers. Because it is difficult to directly and accurately measure for the tractive force, in the U.S. and Japan, the tractive force is estimated and used through the hydraulic experiment on revetment technique. In Korea, research has been conducted to directly measure tractive force recently, including the development of a device to measure one-dimensional tractive force using shear plates. Because information and communication technologies such as Internet of Things (IoT) and Big Data due to 4th Industrial Revolution have become more accessible to individuals due to convergence with daily life, it is possible to improve measurement convenience at the low price of tractive force measurement devices using a data logger developed with this technology.
The purpose of this study is to develop a device to integrate IoT technology into the developed tractive force system using arduino, which is capable of monitoring data using the internet and smart phone. The limitation of the measuring device using the arduino is that the transmission delay is caused by the WiFi module during the data transmission for monitoring. In order to compensate for these limitations while maintaining the usefulness of the measuring device, a method has been developed in this study to transmit a 3 minute mean value using a data averaging technique. For the verification of the developed arduino measuring device, 3-dimensional tractive force measurement device using arduino and 3-dimensional tractive force measurement device using a data logger were compared. In addition, by analyzing the hydraulic characteristic of the high speed channel, the tractive force calculated using the theoretical equation (Reach-Averaged method, TKE method, Reynolds stress method), and the measurement value of tractive force using the arduino and the measurement value of tractive force using a data logger were compared.
The results of the experiment showed that the measured data using the arduino has more data deviation than the measured data using the data logger and it was confirmed that the measured data using the arduino is somewhat lower in terms of precision. The tractive force measured by the tractive force system was similar to the tractive force of the Reach-Averaged method calculated using 0.012 of the roughness coefficient of acrylic. The numerical value of tractive force TKE and Reynolds stress method was very different. In order to use TKE and Reynolds stress method that analyzes the tractive force due to turbulence characteristic, the turbulent velocity field must be measured, but it is judged that the main reason is that sufficient velocity data cannot be obtained under the high velocity conditions. Considering the limitation of measurement of various hydraulic characteristic value such as the turbulent velocity in the high velocity, it is considered that the device for measuring the direct tractive force using arduino is very useful.

목차 (Table of Contents)

• CONTENTS
• LIST OF TABLE iv
• LIST OF FIGURES vi
• LIST OF SYMBOLS, ABBREVIATIONS, AND UNITS OF
• MEASURE xii
• ABSTRACT xv
• Chapter 1 Introduction 1
• 1.1 Research Background and Purpose 1
• 1.2 Domestic and Foreign Research Trend 4
• Chapter 2 Theoretical Background 14
• 2.1 Arduino 14
• 2.1.1 Arduino Theory 18
• 2.1.2 Measurement System Utilizing Arduino 23
• 2.2 Tractive Force 32
• 2.2.1 Measurement Method of Tractive Force 35
• 2.2.2 Measurement System of Tractive Force Utilizing
• Arduino 45
• 2.3 PIV 51
• Chapter 3 Hydraulic Experiment 55
• 3.1 Preparation of Experiment 55
• 3.1.1 Three-Dimensional Tractive Force Measurement
• Device 55
• 3.1.2 Hydraulic Characteristic Measuring Device 60
• 3.1.2.1 Non-Sloping High Speed Channel 60
• 3.1.2.2 Discharge Measurement Device 62
• 3.1.2.3 Water Level Measurement Equipment 64
• 3.1.2.4 Velocity Rate of a Fluid Measurement Device 66
• 3.2 Experimental Condition 71
• 3.3 The Results of Experiment 72
• 3.3.1 Experiments Results by Data Logger 74
• 3.3.1.1 Case 0.05_D 74
• 3.3.1.2 Case 0.06_D 78
• 3.3.1.3 Case 0.07_D 82
• 3.3.2 Experiment Result Using Arduino 86
• 3.3.2.1 Case 0.05_A 86
• 3.3.2.2 Case 0.06_A 90
• 3.3.2.2 Case 0.07_A 94
• Chapter 4 Result Analysis 98
• 4.1 Hydraulic Experiment Result Analysis 98
• 4.2 Theoretical Equation and Comparative Analysis 100
• 4.2.1 Reach-Averaged Method 100
• 4.2.2 TKE Method 104
• 4.2.3 Reynolds Stress Method 106
• 4.3 Equation Comparison and Analysis 108
• Chapter 5 Conclusion 115
• REFERENCES 117