A Study Of The Influence Of Of Canyon Sinuosity On The Flow And Deposition Of Turbidity Currents In Submarine Canyons

With the continuous development of computer and computing technology,numerical simulation has gradually become one of the important methods for studyingturbidity currents. In this study, a three-dimensional computational model based onReynolds-averaged Navier-Stokes equation and buoyancy modified turbulencek model is used to study the flow and deposition of turbidity currents insubaqueous arc-shaped canyons with four different sinuosity. It is not only confirmedthe known facts of turbidity currents in sinuous submarine canyon such as the spill ofturbidity currents on floodplain and self-levee-building, but also obtained thefollowing findings concerning the influence of sinuosity on turbidity currents insinuous arc-shaped channels:(1) As channel sinuosity increases, the flow velocity ofturbidity currents in the downstream direction decreases while it influenced areaspreads;(2) As channel sinuosity increases, the secondary flow at inner bend apexchanges from separating flow to uni-directional to the outer band apex;(3) Afterrepeated events of turbidity currents, the settled layer on the inner bank floodplainshows upward convex shape, and its peaks moves outwards with increasing insinuosity after multiple flow events; while that of outer bank presents a upwardconcave shape，and its degree of concave decreases with increasing in sinuosity aftermultiple flow events;(4) As channel sinuosity increases，the concentration ofturbidity currents on the floodplain increases, while that on canyon bottom decrease;(5) The higher the sinuosity of the channel, the faster larger particles in the currentsdeposited;(6) Deposition thickness upstream increases with increasing sinuosity,while that of downstream decreases;(7) After repeated flow events, the canyontopography will be changed by erosion in inner bank and deposition in outer bank ofturbidity currents, the cross-section shape changes gradually from arc to trapezoidal,while the canyon centerline shows a small migration towards inner bank, and it seems the transition speed of canyon with lower sinuosity is faster. This conclusions mayhelp us to deduce the original environmental, mechanisms of relevant turbidity currentand possible hydrocarbon reservoir conditions from the field observation or bore-holedata analyses of turbidites.