Fundamentals and applications of arrangements of pulsed fluid jets

点击翻译按钮获取中文摘要

Individual pulsed fluid jets are often associated with the locomotion of aquatic animals such as squid, octopuses, nautiluses, jellyfish and even scallops. In industry, they find applications in water jet machining, dentistry and the cooling of electronic components. It therefore comes as no surprise that significant research has been devoted to the fluid dynamics of the individual pulsed jet and the development of its applications. Very little, however, is known about the fluid dynamics of arrangements of two or more pulsed jets. Arrangements of pulsed jets are also observed in aquatic animals (e.g., salps, siphonophores) and have many promising applications that can have a significant impact on health and innovation in Canada. For example, our bladders fill intermittently from two pulsed ureteric jets. The behaviour of these jets is known to change in the presence of adverse urinary conditions such as kidney stones, which affects 1 in 10 Canadians. A better understanding of the fluid dynamics of pairs of pulsed jets can therefore lead to a link between bladder ultrasound flow patterns and the health of the urinary system. In engineering, pulsed jets can be used as an energy-efficient means of locomotion for autonomous aquatic robots and vehicles. This research program will therefore pioneer knowledge of the fluid dynamics of pulsed jet arrangements and develop new advanced applications and technologies to Canada's benefit. This program is arranged into three principal directions or axes. In Research Axis 1, we will conduct parametric, three-dimensional, time-resolved numerical and experimental studies of two single-pulsed fluid jets in free and confined environments. This research will significantly advance knowledge of the fluid dynamics of pairs of pulsed jets, which will provide much needed insight for certain physiological and pathological urinary and cardiac flows. The knowledge generated from this axis is also expected to bolster innovation in such applications as aquatic vehicle locomotion, mitigation of flow separation and industrial/batch mixing of shear-sensitive substances. In the following research axes, we will research and develop the use of pulsed jets for the latter two applications. In Research Axis 2, we will investigate the ability of an array of pulsed jets to mitigate flow separation on a flat plate (experimentally) and over airfoils (numerically). This research is expected to lead to a novel strategy and technology to mitigate flow separation over aircraft wings for a dynamic range of angles of attack, thereby improving fuel economy. In Research Axis 3, we will investigate and model optimal, low shear mixing protocols in a confined circular environment through numerical simulations and develop a pulsed-jet-controlled batch mixing device. The resulting technology is expected to markedly improve mixing times at a reduced energy expense for the mixing of shear-sensitive substances (e.g., certain food products).