Fig 1 - uploaded by Farah A. Naser
Content may be subject to copyright.
![Different types of fish fins. Pectoral Fin shape has important effects for swimming hydrodynamics, usual habitat uses and energetics as shown in [14]. Many different variables that describe fin shape, one of them is the aspect ratio (Ar), which can be defined as the measure of the relative narrowness of the fin, in labriform swimming fish, for example, pectoral fin shape varies from low Ar (i.e. ≤ 2.0) as in paddle-shaped fins, to relatively high Ar (i.e.≥ 4.5) [15-16]. In recent pieces of research show that labriform based fish with a lower Ar of paddle-shaped, swims more slowly and occupy a less energetics areas on the reef [17-18] compared to labriform-based with higher Ar of wing-shaped fins. Practical studies have confirmed casual observations that labriform-based with wing-shaped fins use a flapping mode while labriform-based with paddle-shaped fins use a rowing or intermediate mode [16]. A composition of these two studies of flapping and rowing gives support for the rowing-flapping model study. Finally, it is worthy to observe that fish that swims with pectoral fin flapping can achieve speeds higher than that of BCF swimmers of the same size, while the rowing pectoral fins have lower than performance than expected [14]. Labriform mode with pectoral fin motions with steady swimming concluded as Hydrolagus [19], Gomphosus [14,20], Cirrhilabrus [14], Tautoga, Scarus [21], and Lactoria, Tetrasomus [22] [33]. The objective of the present study is to investigate the efficient production of thrust during the rowing motion of Labriform mode, in which the thrust is provided by pectoral fins only. Three concave fins have different sizes is proposed, in order to choose the optimum one, the fins have been experimentally validated by computational fluid dynamics (CFD) analysis provided by Solidworks® to show the most proper one that produces the highest thrust and lowest drag forces, all the three fins have the same length but with different surface areas, such that each fin has an aspect ratio different from the others. It is well known that the lowest aspect ratio fin will produce the maximum thrust in](profile/Mofeed-Rashid/publication/341193800/figure/fig1/AS:888313888137216@1588801943565/Different-types-of-fish-fins-Pectoral-Fin-shape-has-important-effects-for-swimming.jpg)
Different types of fish fins. Pectoral Fin shape has important effects for swimming hydrodynamics, usual habitat uses and energetics as shown in [14]. Many different variables that describe fin shape, one of them is the aspect ratio (Ar), which can be defined as the measure of the relative narrowness of the fin, in labriform swimming fish, for example, pectoral fin shape varies from low Ar (i.e. ≤ 2.0) as in paddle-shaped fins, to relatively high Ar (i.e.≥ 4.5) [15-16]. In recent pieces of research show that labriform based fish with a lower Ar of paddle-shaped, swims more slowly and occupy a less energetics areas on the reef [17-18] compared to labriform-based with higher Ar of wing-shaped fins. Practical studies have confirmed casual observations that labriform-based with wing-shaped fins use a flapping mode while labriform-based with paddle-shaped fins use a rowing or intermediate mode [16]. A composition of these two studies of flapping and rowing gives support for the rowing-flapping model study. Finally, it is worthy to observe that fish that swims with pectoral fin flapping can achieve speeds higher than that of BCF swimmers of the same size, while the rowing pectoral fins have lower than performance than expected [14]. Labriform mode with pectoral fin motions with steady swimming concluded as Hydrolagus [19], Gomphosus [14,20], Cirrhilabrus [14], Tautoga, Scarus [21], and Lactoria, Tetrasomus [22] [33]. The objective of the present study is to investigate the efficient production of thrust during the rowing motion of Labriform mode, in which the thrust is provided by pectoral fins only. Three concave fins have different sizes is proposed, in order to choose the optimum one, the fins have been experimentally validated by computational fluid dynamics (CFD) analysis provided by Solidworks® to show the most proper one that produces the highest thrust and lowest drag forces, all the three fins have the same length but with different surface areas, such that each fin has an aspect ratio different from the others. It is well known that the lowest aspect ratio fin will produce the maximum thrust in
Source publication
Swimming performance underlies the biomechanical properties and functional morphology of fish fins. In this article, a pair of concave fin has been suggested, which is inspired from Labriform-mode Swimming fish. First, three concave fins with different sizes are proposed in order to choose the optimum size. All three fins have the same length but w...
Contexts in source publication
Context 1
... are more efficient when the flow of chordwise fin is small. While they are more efficient at higher speeds in lift-based motion. There are many different kinds of fish fins. Each fin of a fish helps in swimming and maneuvering. For each fish, generally, there are five main fins follows: Dorsal, Pelvic, Caudal (tail), Anal and Pectoral as shown in Fig. 1. Dorsal fins are located either on the back of the fish or its top, it helps the fish during sharp turning or stops. Fish may have up to three different kinds of dorsal fins, known as proximal, middle, and distal dorsal fins, however, many fish have just two dorsal fins with the middle and distal fins merged together. Dorsal fins types ...
Context 2
... area approximately as an ellipse form where its size gradually changes through the longitudinal axis of the body in order to reduce water resistance. The 3D design of the robot is then analyzed with CFD, to ensure that the robot can withstand the surrounding environmental conditions in two cases of power and recovery strokes as shown in Fig. 10 we can see the flow velocity decrease behind the robot as expected, this little degradation in speed will lead to a change in pressure as shown in Fig. 11, however, the maximum reached value of pressure is not so much larger than the already set value of pressure of 101325 Pa at the beginning of the simulation, this ensures the ...
Context 3
... The 3D design of the robot is then analyzed with CFD, to ensure that the robot can withstand the surrounding environmental conditions in two cases of power and recovery strokes as shown in Fig. 10 we can see the flow velocity decrease behind the robot as expected, this little degradation in speed will lead to a change in pressure as shown in Fig. 11, however, the maximum reached value of pressure is not so much larger than the already set value of pressure of 101325 Pa at the beginning of the simulation, this ensures the swimming robot has the ability to stand the external flow changes. Following our results in [11] and [25] where a variation in input signal of power stroke speed ...
Context 4
... is not so much larger than the already set value of pressure of 101325 Pa at the beginning of the simulation, this ensures the swimming robot has the ability to stand the external flow changes. Following our results in [11] and [25] where a variation in input signal of power stroke speed and recovery stroke speed had taken place as shown in Fig. 12, the results showed that the optimum velocity when the power stroke speed is one-third of the recovery stroke speed, the reader can refer to these references for further information, where 1, 2, 3, 4, and 5 represent five signals of power to recovery stroke ratio. The signal is set to complete the power stroke during the first ...
Context 5
... recovery stroke at the last two-thirds of the time. The starting angle of rotation is set to 50˚. The robot will rotate in a 100åmplitude (i.e. from 50˚to 50˚to -50˚). The frequency is set to 1.515 Hz to match the servo motor specifications. A computational domain of (1x 0.65 x 0.65) meter in (length, width, and height) has been used as shown in Fig. 13 to match the dimension of the physical swimming pool, which is made of acrylic plastic material. The servomotors of robot pectoral fins are controlled by an Atmega microcontroller. While the torque is calculated at the highest required speed at the power to recovery ratio of 5:1, which the maximum value is 0.23 N.m. This value can be ...
Context 6
... the torque is calculated at the highest required speed at the power to recovery ratio of 5:1, which the maximum value is 0.23 N.m. This value can be translated to match 3 Kg/cm where a Hitec 35086W HS-5086WP waterproof digital servomotor has been used as shown in Fig.14. All plastic parts such as the robot body, fins, joints have been printed by a 3D printer of PLA material. ...
Context 7
... robot body, fins, joints have been printed by a 3D printer of PLA material. The robot motion is captured through Kodak high-resolution camera at a frame rate of 30 frames per second. Motion commands are sent to the controller via the HC-06 Bluetooth module, four 1.5V AA batteries were used to supply the robot with the required energy as shown in Fig. 15. Water density is assumed at 1000 kg/m3. It is worthy to mention that all inner electronic devices are covered with NANO PROTECH coating technology spray to protect them from direct contact with water. Finally, for further validation of the above design, the efficiency has been calculated of our robot in terms of Strouhal number as ...
Context 8
... 15. Water density is assumed at 1000 kg/m3. It is worthy to mention that all inner electronic devices are covered with NANO PROTECH coating technology spray to protect them from direct contact with water. Finally, for further validation of the above design, the efficiency has been calculated of our robot in terms of Strouhal number as shown in Fig. 16, which Strouhal number for biological fish is usually in the range of 0.05-0.6. From Fig. 16 can be noticed that it can get about 3.8 value of Strouhal number at 3:1 ratio. This value is much greater than that range one reason is that when physical fish swims, it does not depend purely on its pectoral fins as presented in this study ...
Context 9
... devices are covered with NANO PROTECH coating technology spray to protect them from direct contact with water. Finally, for further validation of the above design, the efficiency has been calculated of our robot in terms of Strouhal number as shown in Fig. 16, which Strouhal number for biological fish is usually in the range of 0.05-0.6. From Fig. 16 can be noticed that it can get about 3.8 value of Strouhal number at 3:1 ratio. This value is much greater than that range one reason is that when physical fish swims, it does not depend purely on its pectoral fins as presented in this study rather it can use tail and other fins also. This result in a relative low swimming velocity and ...
Context 10
... are more efficient when the flow of chordwise fin is small. While they are more efficient at higher speeds in lift-based motion. There are many different kinds of fish fins. Each fin of a fish helps in swimming and maneuvering. For each fish, generally, there are five main fins follows: Dorsal, Pelvic, Caudal (tail), Anal and Pectoral as shown in Fig. 1. Dorsal fins are located either on the back of the fish or its top, it helps the fish during sharp turning or stops. Fish may have up to three different kinds of dorsal fins, known as proximal, middle, and distal dorsal fins, however, many fish have just two dorsal fins with the middle and distal fins merged together. Dorsal fins types ...
Context 11
... area approximately as an ellipse form where its size gradually changes through the longitudinal axis of the body in order to reduce water resistance. The 3D design of the robot is then analyzed with CFD, to ensure that the robot can withstand the surrounding environmental conditions in two cases of power and recovery strokes as shown in Fig. 10 we can see the flow velocity decrease behind the robot as expected, this little degradation in speed will lead to a change in pressure as shown in Fig. 11, however, the maximum reached value of pressure is not so much larger than the already set value of pressure of 101325 Pa at the beginning of the simulation, this ensures the ...
Context 12
... The 3D design of the robot is then analyzed with CFD, to ensure that the robot can withstand the surrounding environmental conditions in two cases of power and recovery strokes as shown in Fig. 10 we can see the flow velocity decrease behind the robot as expected, this little degradation in speed will lead to a change in pressure as shown in Fig. 11, however, the maximum reached value of pressure is not so much larger than the already set value of pressure of 101325 Pa at the beginning of the simulation, this ensures the swimming robot has the ability to stand the external flow changes. Following our results in [11] and [25] where a variation in input signal of power stroke speed ...
Context 13
... is not so much larger than the already set value of pressure of 101325 Pa at the beginning of the simulation, this ensures the swimming robot has the ability to stand the external flow changes. Following our results in [11] and [25] where a variation in input signal of power stroke speed and recovery stroke speed had taken place as shown in Fig. 12, the results showed that the optimum velocity when the power stroke speed is one-third of the recovery stroke speed, the reader can refer to these references for further information, where 1, 2, 3, 4, and 5 represent five signals of power to recovery stroke ratio. The signal is set to complete the power stroke during the first ...
Context 14
... recovery stroke at the last two-thirds of the time. The starting angle of rotation is set to 50˚. The robot will rotate in a 100åmplitude (i.e. from 50˚to 50˚to -50˚). The frequency is set to 1.515 Hz to match the servo motor specifications. A computational domain of (1x 0.65 x 0.65) meter in (length, width, and height) has been used as shown in Fig. 13 to match the dimension of the physical swimming pool, which is made of acrylic plastic material. The servomotors of robot pectoral fins are controlled by an Atmega microcontroller. While the torque is calculated at the highest required speed at the power to recovery ratio of 5:1, which the maximum value is 0.23 N.m. This value can be ...
Context 15
... the torque is calculated at the highest required speed at the power to recovery ratio of 5:1, which the maximum value is 0.23 N.m. This value can be translated to match 3 Kg/cm where a Hitec 35086W HS-5086WP waterproof digital servomotor has been used as shown in Fig.14. All plastic parts such as the robot body, fins, joints have been printed by a 3D printer of PLA material. ...
Context 16
... robot body, fins, joints have been printed by a 3D printer of PLA material. The robot motion is captured through Kodak high-resolution camera at a frame rate of 30 frames per second. Motion commands are sent to the controller via the HC-06 Bluetooth module, four 1.5V AA batteries were used to supply the robot with the required energy as shown in Fig. 15. Water density is assumed at 1000 kg/m3. It is worthy to mention that all inner electronic devices are covered with NANO PROTECH coating technology spray to protect them from direct contact with water. Finally, for further validation of the above design, the efficiency has been calculated of our robot in terms of Strouhal number as ...
Context 17
... 15. Water density is assumed at 1000 kg/m3. It is worthy to mention that all inner electronic devices are covered with NANO PROTECH coating technology spray to protect them from direct contact with water. Finally, for further validation of the above design, the efficiency has been calculated of our robot in terms of Strouhal number as shown in Fig. 16, which Strouhal number for biological fish is usually in the range of 0.05-0.6. From Fig. 16 can be noticed that it can get about 3.8 value of Strouhal number at 3:1 ratio. This value is much greater than that range one reason is that when physical fish swims, it does not depend purely on its pectoral fins as presented in this study ...
Context 18
... devices are covered with NANO PROTECH coating technology spray to protect them from direct contact with water. Finally, for further validation of the above design, the efficiency has been calculated of our robot in terms of Strouhal number as shown in Fig. 16, which Strouhal number for biological fish is usually in the range of 0.05-0.6. From Fig. 16 can be noticed that it can get about 3.8 value of Strouhal number at 3:1 ratio. This value is much greater than that range one reason is that when physical fish swims, it does not depend purely on its pectoral fins as presented in this study rather it can use tail and other fins also. This result in a relative low swimming velocity and ...
Similar publications
The article presents an aerodynamic analysis of the aircraft model. The process of constructing the physical model began with the development of geometry. Preliminary design was made using SolidWorks program, giving the desired shape with as many details as the method allowed. It had to be made precisely, because later it was to be printed on a 3D...
Citations
... PLA is a commercially available material for printing samples. Polylactic acid (PLA) is extruded from nozzle tips as components or support materials onto an FDM machine-working platform [6,7]. ...
... Furthermore, compared to ABS, 3D-printed PLA products have better mechanical characteristics [25]. But PLA has a drawback because it is brittle by nature [6]. Table 1 displays the characteristics and specifications of PLA filament. ...
... This technology selectively joins materials layer by layer to build the required component based on a 3D Computer-Aided Design (CAD) model [3]. Non-metallic 3D printing frequently employs materials such as Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) [4]. PLA, in particular, has gained popularity due to its affordability, wide availability, and lightweight properties [5]. ...
... For each run, every piece of geometry was measured three times. The average percentage deviation for the geometry was then determined using Equations (3)(4)(5) [33]. ...
... For fishes propelled by pectoral fins (such as labriform), the shape of the pectoral fin ranges from a low aspect ratio of paddle fins (i.e., AR ≤ 2.0) to a relatively high aspect ratio (i.e., AR ≥ 4.5) [37]. Naser et al. [38] studied the effects of different shapes of pectoral fins on swimming velocity and efficiency and showed that high aspect ratio pectoral fins have less propulsion resistance and high propulsion efficiency, but they are more Figure 3 shows the shape characteristics and dimensions of the pectoral and caudal fins of the designed prototype. Some scholars have studied the relationship between the shape of the pectoral fins and the swimming velocity of fish swimming with median and/or paired fin (MPF) mode and found that the fishes which swim at a slow speed have more symmetrical circular pectoral fins [36,37]. ...
... For fishes propelled by pectoral fins (such as labriform), the shape of the pectoral fin ranges from a low aspect ratio of paddle fins (i.e., AR ≤ 2.0) to a relatively high aspect ratio (i.e., AR ≥ 4.5) [37]. Naser et al. [38] studied the effects of different shapes of pectoral fins on swimming velocity and efficiency and showed that high aspect ratio pectoral fins have less propulsion resistance and high propulsion efficiency, but they are more likely to lead to heading deviation and affect stability. Considering the stability and maneuverability of the prototype during swimming, the shape characteristics of the designed pectoral fin are shown in Figure 3, and its aspect ratio is 0.71. ...
Locomotion control of synergistical interaction between fins has been one of the key problems in the field of robotic fish research owing to its contribution to improving and enhancing swimming performance. In this paper, the coordinated locomotion control of the boxfish-like robot with pectoral and caudal fins is studied, and the effects of different control parameters on the propulsion performance are quantitatively analyzed by using hydrodynamic experiments. First, an untethered boxfish-like robot with two pectoral fins and one caudal fin was designed. Second, a central pattern generator (CPG)-based controller is used to coordinate the motions of the pectoral and caudal fins to realize the bionic locomotion of the boxfish-like robot. Finally, extensive hydrodynamic experiments are conducted to explore the effects of different CPG parameters on the propulsion performance under the synergistic interaction of pectoral and caudal fins. Results show that the amplitude and frequency significantly affect the propulsion performance, and the propulsion ability is the best when the frequency is 1 Hz. Different phase lags and offset angles between twisting and flapping of the pectoral fin can generate positive and reverse forces, which realize the forward, backward, and pitching swimming by adjusting these parameters. This paper reveals for the first time the effects of different CPG parameters on the propulsion performance in the case of the synergistic interaction between the pectoral fins and the caudal fin using hydrodynamic experimental methods, which sheds light on the optimization of the design and control parameters of the robotic fish.
... It works with a 3D Computer-Aided Design model to selectively join materials layer by layer to create the required component [3]. Materials such as Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA) are commonly used in non-metallic 3D printing [4]. Affordability, availability, and weightlessness are why PLA has been used so widely [5]. ...
... where θ Fin (t) represents the instantaneous angular position of the base of the fin, A is the amplitude of the wave generated by the fin, and w f is the angular frequency which can be given as w f = 2π f [29]. The main goal, at this stage, is to determine the hydrodynamic forces applied to the pectoral fin while moving toward or backward within different fin beat angles. ...
... The parameters used throughout this work are derived either directly or empirically and are listed as shown in Table II. The added mass/inertia of the swimming robot is derived following equations (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) by approximating the body to a prolate spheroid shape. ...
The use of swimming robots has increased widely in recent years due to the need of using them in situations where human intervention is difficult or not allowed. Exploring depths of seas, military interventions, or entering areas where the amount of water pollution is high that may threaten the lives of divers. In such cases, the best alternative for humans is to use swimming robots. This paper presents a swimming robot based on Labriform swimming mode. First, it starts with an analytical study of the effect of the fins shape on the performance of a robotic fish. The suggested design of the pectoral fins is concave. The effect of such a design would help largely in achieving the highest thrust in comparison to flat designs provided in the literature. Secondly, a variation in the velocity between the power and recovery strokes is accomplished and a maximum thrust can be obtained when the velocity of the power stroke is three times the velocity of recovery stroke. Thirdly, the kinematics and dynamics of the swimming robot are derived and an evaluation of the total hydrodynamic forces that are exerted on the robot's body is studied via the computational fluid dynamics method from SOLIDWORKS R platform. Finally, the obtained results are compared to other designs in the literature in terms of some dimensionless numbers of biological fish to examine the efficiency. The proposed design has been validated theoretically and examined experimentally. The results of the simulation and practical experiments confirmed the validity of the design.
... where CD is the drag coefficient, which is a function of the Reynolds number Naser et al. (2020). The relationship between CD and Re for a micro-robot can be experimentally approximated by Schlichting (1955) = 24 < 1, ...
The weakness of sperm motility arouses the interest of many researchers due to its effect on the success of fertilization cases in couples. In recent years, this has led to the emergence of new technologies such as controllable micro-motor systems which still under evolution. The previous works that concerned with the design of micro-motors in assisting of sperm for moving or change their direction, were not autonomous-based systems. Further, it is worth noting, designing an autonomous micro-robot that emulates sperm in size and behavior is a difficult challenge. Therefore, this paper presents the first step in designing this micro-robot, by drawing the physical structure of micro-robot based on figuring the biological structure of sperm and its behavior to complete the fertilization process. While the main objective is to design a Micro-actuator system, based on the piezoelectric technique for generating a forward thrust force of the micro-robot. The simulation of the proposed design has been conducted by the Solidworks platform and MATLAB, to examine the performance of the micro-actuator system, in which the results describe the requirement for achieving an actuation system.
... Most of them are propelled by different sizes and shapes of flat pectoral fins. This work presents an extension to our previous works [28][29][30][31], in which the concave design has proved its efficiency in producing larger thrust than flat fins. ...
The ability of fish to change the swimming direction is directly related with maneuvering performance. One of the maneuvering aspects is the steering process. Maneuverability can be defined as the ability to turn in a confined area and it is measured as the turning radius trajectory in terms of the body length (R/BL, where R is defined as the turning radius and BL defined as the total body length). This paper aims to develop a swimming robot of labriform swimming mode with good steering performance. The steering process is achieved by one degree of freedom (1-DOF) represented by two concave-shaped pectoral fins. The steering mechanism adopted in this work is based on the differential drive principle. This principle is carried out by varying the right/left fins velocities. Different radii have been observed with four different cases of velocities. Diving underwater, is another aspect that has been taking into account during this work. The designed robot uses a mass sliding mechanism to change its center of gravity, and consequently, controlling the pitch angle and hence the depth of the robot. The designed glider robot is able to achieve about 40° of pitch angle and swims for a depth of approximately 30 cm underwater. The results of these experiments showed the success of the proposed robot to steer and dive efficiently.
... Despite of large amount of studies over a few past years for swimming robots that are propelled by different sizes and shapes of pectoral fins was an attractive subject by many researchers, the effect of concave-shaped fin in rowing motion of labriform mode has not been investigated yet, such a shape will help largely in producing a large amount of thrust force when the fins start pushing toward the backward of the body, while minimizing the drag force to minimum when the fins returns back to its original position a comprehensive study of the effect of concave shape design of pectoral fins in generating forward thrust can be found as in [22][23][24][25]. ...
... There are two strokes of the fin movement; the first one is the power stroke that occurs when the fins move toward the back of the body with velocity V power , while the second one is the recovery stroke, which occurs when the fins returned to their initial position with velocity V recovery [22][23][24][25]. In order to get thrust, the ratio V power /V recovery is varied to obtain the optimum turning radius as shown in Fig.2. ...
... Tapered, high Ar fins are usually used by the fish to produce lift-based thrust and maintain high speeds, whereas rounded, low Ar fins are basically associated with rowing fin oscillation of drag-based thrust and effective at low-speed maneuverability. The success of using this fin in producing a large thrust during power stroke while minimizing drag force during recovery stroke, has been proved in our previous work in, readers can freely refer to [25] for further analysis. ...
The aim of this study is to develop a swimming robot with good steering performance, in which the steering behavior is achieved by one degree of freedom (1-DOF) represented by a two concave-shaped pectoral fins. The steering mechanism adopted here based on differential drive principle. This principle is carried out by varying the right/left fins velocities. Different radii have been achieved with four different cases of velocities. The proposed design has been validated theoretically via Solidworks platform and proved practically in a physical swimming pool. A minimum turning radius achieved is 0.40 of body length (BL).
The use of swimming robots has increased widely in recent years due to the need of using them in situations where human intervention is difficult or not allowed. Exploring depths of seas, military interventions, or entering areas where the amount of water pollution is high that may threaten the lives of divers. In such cases, the best alternative for humans is to use swimming robots. This paper presents a swimming robot based on Labriform swimming mode. First, it starts with an analytical study of the effect of the fins shape on the performance of a robotic fish. The suggested design of the pectoral fins is concave. The effect of such a design would help largely in achieving the highest thrust in comparison to flat designs provided in the literature. Secondly, a variation in the velocity between the power and recovery strokes is accomplished and a maximum thrust can be obtained when the velocity of the power stroke is three times the velocity of recovery stroke. Thirdly, the kinematics and dynamics of the swimming robot are derived and an evaluation of the total hydrodynamic forces that are exerted on the robot’s body is studied via the computational fluid dynamics method from SOLIDWORKS® platform. Finally, the obtained results are compared to other designs in the literature in terms of some dimensionless numbers of biological fish to examine the efficiency. The proposed design has been validated theoretically and examined experimentally. The results of the simulation and practical experiments confirmed the validity of the design.
