A Fundamental Study On Wave/current-induced Artificial Upwelling

Upwelling is an oceanographic phenomenon that involves deep ocean water(DOW) towards the ocean surface, replacing the surface water. The DOW is usually dense, cooler, and nutrient-rich, which stimulates the growth and reproduction of primary producers such as phytoplankton for the surface water, and makes the new factory of the world in further.Inspired by the phenomenon, artificial upwelling technology is proposed as to achieve the upwelling in artificial ways by scientists.To drive the artificial upwelling, many different ocean devices were applied around the world. Undoubtedly, the most convenient and fast way is to utilize the intrinsic motion of the ocean - the waves and the currents. However, most of the wave or current driven artificial upwelling devices are relatively complex and small-scale,which makes the artificial upwelling low efficiency and high cost, and was limited in a small area of the sea. In addition, these devices are often destroyed by the power of the sea in a short period of the sea trial, which makes the result not so ideal.Therefore, the key of the question is to design a high-efficiency and low-cost process of artificial upwelling, which utilizes the ocean waves and currents as much as possible without other energy input, and works well in the ocean.This issue provides an artificial upwelling method utilizing the motive energy of the ocean to induce a continuous upwelling,the apparatus thereof is simple and cheap,which is easy for large-scale deploying.This issue is established in a study of wave/current-induced artificial upwelling theory. The distinguishing feature of the study lies in: it uses the analytical method of water wave hydrodynamics to apply the non-linear water head characteristic of the linear waves in artificial upwelling area, and calculates the upwelling water head on quantitative research, which provides a new idea of inducing artificial upwelling.The model of this issue is based on the basic equations of small amplitude waves and Bernoulli equations. It is proved by calculation that the motive artificial upwelling water head exists in the deep sea, and has the ability to induce artificial upwelling by a floating system when the resistance from the ocean and the floating device could be overcome.The main research contents of this issue are summarized as follows:Based on the access to the domestic and foreign literature, the first chapter discusses the background, the purposes, and the significance of the study of artificial upwelling. It also introduces the generation technology and the achievements of artificial upwelling around the world, and the advantages and shortcomings respectively in current research. The main idea of the issue is also elucidated in this chapter.The second chapter proposes the wave/current-induced artificial upwelling theory.It is an idea based on the basic theory of the wave mechanics. The main content of this chapter is the process of the theoretical derivation of the artificial upwelling water head.The third chapter mainly discusses the experiments of wave/current-induced artificial upwelling in the wave tank. The main experiments are rely on a floating system, and the contains of three series: the current test; the wave test; and the wave ¤t test. The purpose of experiments is to prove the theory proposed in the second chapter.The forth chapter discusses how to optimize the structure parameters to make the effect of the wave/current induced artificial upwelling better, specially discusses the pipe and the buoy of the floating system, the software used in this section include MATLAB, Fluent, and Flow-3D, and some wave tank experiments and sea trials are referenced.The fifth chapter mainly discusses the internal and external factors that influent the artificial upwelling efficiency for the floating system works in the sea. This section also predicts the ideal upwelling flow rate in some certain sea fields.The sixth chapter summarizes the research work and the achievements of this issue, and also points out the directions for further research.The main innovations of this issue lie in:1. Researching a hydrodynamics method that utilizes the motion of the wave to provide an artificial upwelling water head systematically and designing a wave-induced artificial upwelling apparatus thereof.2. The method proves that the artificial upwelling water head exists in the deep ocean and can be used to induce the artificial upwelling and the value of it can be calculated. In further, the wave-induced artificial upwelling method can be expanded to a wave/current-induced artificial upwelling method, the coupling manner of the wave and the current can be calculated, and the result can be verified by wave/current tank experiments.3. Optimizing the floating system applied in the wave-induced artificial upwelling technique preliminarily, analyzing the interior and external influencing factors thereof,and predicting the induced artificial upwelling flow rate in a certain sea area preliminarily.