Determination Whether a Large Scale Tesla Valve Could Be Applicable As a Fish Passage
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Determination whether a large scale Tesla valve could be applicable as a fish passage Additional Thesis K. Keizer Supervisor: N.C. van de Giesen Delft University of Technology, Department of Civil Engineering, Stevinweg 1, 2628CN Delft, PO-Box 5048, The Netherlands October, 2016 1 Special thanks to: Prof. dr. ir. Nick van de Giesen - Water Resources Management Prof. dr. ir. Wim Uijttewaal - Experimental Hydraulics Sander de Vree - Coordinator Laboratory Hans Tas - Research Assistants & Arno - Research Assistants (Trainee) Frank Kalkman - Technician & Jaap van Duin - Technician Jasper Arntz - Specialist at Arcadis 2 Table of contents Abstract……………………….………….……………………………………………………… 4 1. Introduction………………...………………………………………………………………… 4 2. Background information.......………………………………………………………………… 5 3. Materials and Methods………………………………………………………………………. 7 3.1 Experiment I……...………………………………………………………………… 7 3.2 Experiment II……..………………………………………………………………… 7 3.3 Experiment III…….………………………………………………………………… 8 4. Results and discussion……...………………………………………………….…..………… 11 4.1 Experiment I……………………………………………………………….……….. 11 4.2 Experiment II……...……..….……………………………………………………… 11 4.2.1 Flow depth…...…………………………………………………………... 11 4.2.2 Flow velocity…...………………………………………………………... 13 4.2.3 Energy dissipation...……………………………………………………... 14 4.3 Experiment III…….………………………………………………………………… 15 4.3.1 Energy dissipation………...…..…..……………………………………… 16 4.3.2 Critical flow velocity……..……………………………………………… 18 4.3.3 Pond depth………………...……………………………………………… 19 5. Conclusion and recommendations…………….………………………………………….….. 22 References………………………………………………………………………………………. 24 Appendix - Table of contents (detailed)……………….…………….…………………………. 25 Appendix A - Migration of species, their needs and requirements with respect to habitats…….. 26 Appendix B - Measuring methods……………………………………………………………… 30 Appendix C - Measurement points……………………………………………………………... 33 Appendix D - Measuring protocol……………………………………………………………… 34 Appendix E - Experiment III - Calculated & Measured gradients……………………………... 35 Appendix F - Determining Qleakage……………………………………………………………… 36 Appendix G - Calibration velocity meter………………………………………………………. 37 Appendix H - Experiment III - Pond depths……………………………………………………. 38 3 Abstract All around the world many species are dying out locally or entirely due to interferences in their habitats. One of the big problems for marine life is the creation of migration barriers which preclude migrating species to complete their life cycle. Fish passages are a way for migrating species to get around obstructions in a water way. The goal of this research is to determine whether a large scale Tesla valve could be applicable as a fish passage. In a series of three experiments is investigated whether a large scale Tesla valve can meet the requirements as a fish passage. The three experiments have different scales and in each experiment focuses on another part of the requirements. Taking into account all the points from both the ecological and technical perspective it is determined that a large scale Tesla valve could indeed be applicable as a fish passage. However in its original design the valve will only be applicable as fish passage in cases of (very) small gradients and in cases of high gradients only in combination with large discharges. Further research has to be done on shape optimisation, the critical flow velocity and constructional & economic feasibility before the general feasibility of a large scale Tesla valve as fish passage can be determined. 1. Introduction Although the valve has found few applications in the last 100 years the invention recently This additional thesis discusses a series of attracted some interest among researches in the experiments that are conducted as part of the field of microfluidics and could be usable in master Water Resources Management at the Nano-manufacturing techniques. However on a TU Delft. The goal is to determine whether a macro scale the valve could also be interesting large scale Tesla valve could be useable as a as a fish passage. A fish passage is a structure fish passage. that enables migrating species of fish, reptiles and insects to pass a migration barrier (weirs, Nikola Tesla can be considered as one of the locks, pumping stations, rapids, etc.) in a greatest engineers and inventors of all time. In waterway. For an ideal fish passage one wants the scientific world Nikola Tesla is well known a structure with a continuously open for his inventions with respect to electrical connection between the two sides of the circuits. Less known are his inventions in the migration barrier while preventing high flows field of fluid mechanics. In 1916 Nikola Tesla around the barrier (at last the barrier is there invented a valve without moving parts. The for a reason). valve allows a liquid or gas to flow freely in To create an usable fish passage from the one direction, while the flow is blocked in the original patent the valve needs to be scaled up opposite direction. He called his invention the compared to its original size and the closing lid valvular conduit (Figure 1), but this invention of the original design need to be removed became better known as the Tesla valve. (most species don’t like swimming in the dark). These interventions could have a big In his patent Tesla gives an explanation of the influence on the functioning of the valve. principle of the valve: “The interior of the Therefore the research goal of this additional conduit is provided with enlargements, thesis is to determine whether a large scale recesses, projections, baffles, or buckets Tesla valve could be applicable as a fish which, while offering virtually no resistance to passage. the passage of the fluid in one direction, other than surface friction, constitute an almost In this document the steps to get substantiated impassable barrier to its flow in the opposite arguments to say whether the valve is or is not direction.” (Tesla, 1920) usable are elaborated. Figure 1: Original figure from Tesla’s patent of the valvular conduit 4 2. Background information However this also means that there still will be a total number of 14148 obstructions in 2027 A fish passage is, as stated in the introduction, in the Netherlands only. Worldwide the a structure that enables migrating species to number of obstacles for migrating species is pass an artificial migration barrier in a many times greater. waterway. Many fish species, such as salmon, eels and strout, migrate between waters to Different solutions are developed over the spawn, obtain food or seek shelter from years to let migrating species pass by these predators. This can be over long distances obstructions. The solutions can be separated in between fresh and salt waters, but there are a three main groups. First group is the natural lot more species migrating over smaller solutions (Figure 3). The idea of the natural distances as well. Specific information about solutions is to remove the existing barrier and migration of maritime species can be found in replace it by for example a series of cascades. Appendix A.1. When the migration is It this way a more natural flow pattern is obstructed the species cannot complete their created which allows the migrating species to life cycle and can die out locally. This has migrate. The big disadvantage of these happened and still is happening all around the solutions is that the upstream water levels are world. If nothing changes in the current no longer flexible adjustable. situation more and more valuable species will disappear in large regions of the world due to the effect of artificial migration barriers. Figure 3: Natural solution (side view) There are a lot of different places where If a natural solution is not an option the second artificial migration barriers occur. Typical best option is to create a bypass (Figure 4). A bottlenecks for fish migration are bypass is in fact a natural solution, but the fresh/saltwater transitions (pumping stations, creation of a bypass takes up a lot more space sluices), waterways for shipping (locks, dams), since the migration barrier is not removed. The flat areas (polders, shallow culverts) and fast advantage of these solutions over the natural flowing waters (due to weirs, artificial solutions is that the upstream water level still arrowing, etc.). In these places the natural flow can be controlled. pattern of the water is often drastically changed resulting in an obstruction for migrating species. In the elaboration of the European Kaderrichtlijn Water (Europees Parlement & de Raad, 2000) in 2000 there were 15437 Figure 4: Bypass (top view) obstacles for migrating species identified in the Netherlands only. Ten years later 644 fish If the removal of the barrier is not possible and passages were constructed and 645 are planned there is not enough space to create a bypass to build till 2027 (Figure 2). the third group of solutions are the technical solutions (Figure 5). The technical solutions create an artificial connection between the two water sides of the migration barrier. If created the Tesla valve fish passage would be part of this group of solutions. The main advantages of technical solutions are that they often do have small influence on the functioning of the barrier, that they can be created on a relative small area and that passes over high barriers are feasible. Figure 2: Number of obstacles in 2001 and number of obstacles realised or planned in 2011. 5 To provide some rough indication about the requirements of a fish passage river systems