Design, Fabrication and Thrust/Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang Thesis of the Doctor of Philosophy Department of Advanced Technology Fusion Graduate School of Konkuk University Design, Fabrication and Thrust/Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang Thesis of the Doctor of Philosophy Department of Advanced Technology Fusion Graduate School of Konkuk University Design, Fabrication and Thrust/Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang A Dissertation Submitted to the Department of Advanced Technology Fusion and the Graduate School of Konkuk University in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 2010 Approved by Park, Hoon Cheol Major Advisor [...]... Thrust analysis comparison 98 Figure 5-10: Vortex comparison 99 viii List of Tables Table 1-1: Reynolds numbers of fish 2 Table 2-1: Material properties of LIPCA’s layers 26 Table 2-2: Dimension of linkages of the fish robot 35 Table 3-1: Dimension of linkages of the improved fish robot 46 ix ABSTRACT Design, Fabrication and Thrust/ Drag Analysis of Improved Fish Robots. .. Design, Fabrication and Thrust/ Drag Analysis of Improved Fish Robots actuated by Piezoceramic Composite Actuators Quang-Sang Nguyen Department of Advanced Technology Fusion Graduate School of Konkuk University This dissertation focuses on the design, fabrication and thrust/ drag analysis of fish robots actuated by Lightweight Piezoelectric Composite Actuator (LIPCA) In the first model, four LIPCAs were utilized... the design, analysis, and experimentation of fish robots propelled by artificial muscle-type actuators xii 1 Introduction 1.1 Understanding fish swimming After million years of evolution, fish became master of art of propulsive interaction with water with more than 22,000 fish species [1] Due to high density of water, force of gravity on fish body is mostly close to its buoyancy Therefore, some fish. .. body actuated by original LIPCAs To evaluate effect of the larger cross section, drag of the fish robots was estimated by measurement and computational fluid dynamics (CFD) analysis with the ANSYS-CFX software package The CFD analysis and measurement showed about 4.9% and 8.7% increment of drag, respectively, due to about 8.4% larger cross section To identify the mechanism to produce a highest thrust, ... speed of the CLIPCA fish robot actuated by CLIPCAs 83 Figure 4-10: The average thrust of the CLIPCA fish robot for 0.6A tail fin 83 Figure 4-11: The drag of the LIPCA fish robot 84 Figure 4-12: Comparison of drags of the CLIPCA fish robot and the LIPCA fish robot (without electric wires) 84 Figure 4-13: Drag coefficient of fish robots 85 Figure 5-1: Tail fin kinematic... and the boundary layer of water It depends on the wetted area and swimming speed of 1 the fish and property of layer water around the fish Form drag is generated by the distortion of flow around solid bodies and depends on their shape Induced drag is energy lost in the vortices formed by the caudal and pectoral fins when they generate lift or thrust On the other hand, pitch, roll, and yaw motions as shown... surface of bluefish, such as thrust, drag and acceleration [24] Two pressure transducers were used to measure forces on the right and left sides of the tail, as shown in 13 Figure 1-14 As important consideration of fish robots, thrust and drag were studied in literatures The study can be done by careful experimentation and computational fluid dynamics (CFD) Barrett et al built an apparatus for drag measurement... et al built an apparatus for drag measurement to estimate the drag of a robotic fish [25] In this apparatus, the fish robot was towed by a streamlined strut (Figure 1-15) With the same method, the drag of the autonomous fish robot was measured by Listak et al [26] 1.4 Overview of fish robot driven by smart material The fish robots actuated by electromagnetic motor have large size due to a complex mechanism... lift, weight, thrust, and resistance For balancing the vertical forces, fish can create supplement lift force by using their pectoral fins extended For forward swimming, thrust created by fish can be larger than resistance which was called sometime drag Drag has three main components: viscous (or friction drag) , form drag, vortex (or induced drag) Viscous drag is skin friction between the fish and the boundary... diagram of the swimming test 57 Figure 3-14: The swimming speed of the fish robot 59 Figure 3-15: Measured thrust of a rigid connection 59 Figure 3-16: Effect of LIPCA’s inertial force 60 Figure 3-17: Schematic diagram of the thrust measurement 61 Figure 3-18: The average thrust of the fish robot 62 Figure 3-19: The thrust data of the fish robot at a tail beat frequency of . Dimension of linkages of the improved fish robot 46 x ABSTRACT Design, Fabrication and Thrust/ Drag Analysis of Improved Fish Robots actuated by Piezoceramic Composite Actuators Quang-Sang. Department of Advanced Technology Fusion Graduate School of Konkuk University Design, Fabrication and Thrust/ Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators. Design, Fabrication and Thrust/ Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang Thesis of the Doctor of Philosophy