بررسی آزمایشگاهی ارتفاع بدنه جریان غلیظ رسوبی میان‌گذر در نقطه جداشدگی از بستر

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجودانش آموخته کارشناسی ارشد سازه‌های آبی، دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

2 استاد گروه سازه های آبی، دانشکده مهندسی علوم آب، دانشگاه شهید چمران اهواز

چکیده

زمانی که جریان غلیظ زیرگذر در سیالی با لایه‌بندی چگالی حرکت می­کند، با رسیدن به نقطه‌ی هم‌چگالی خود از بستر جداشده و به‌ صورت میان‌گذر درون توده سیال پیرامون حرکت می‌کند. این نقطه که نقطه جداشدگی جریان غلیظ نامیده می‌شود، مرز بین جریان غلیظ زیرگذر و میان‌گذر می‌باشد. در این پژوهش با استفاده از یک مدل فیزیکی به بررسی آزمایشگاهی اثر تغییرات دبی، غلظت و شیب بر روی ارتفاع متوسط جریان غلیظ در نقطه جداشدگی پرداخته شد. تعداد 48 آزمایش در غلظت‌ها و دبی‌های مختلف در فلومی شیب پذیر انجام پذیرفت. بررسی نتایج نشان داد که ارتفاع متوسط بدنه جریان غلیظ در نقطه جداشدگی با افزایش دبی و شیب بستر، افزایش و با افزایش غلظت، کاهش می‌یابد. همچنین با استفاده از تحلیل ابعادی رابطه‌ای برای پیش‌بینی ارتفاع جریان غلیظ در نقطه جداشدگی استخراج شد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Study of Sedimentary Interflow Density Current Body Height in Separation Point From Bed

نویسندگان [English]

  • Leila Hashemi 1
  • Mehdi Ghomeshi 2
1 M.Sc. Graduated Student, Department of Hydraulic Structures, Shahid Chamran University of Ahvaz.
2 Professor, Department of Hydraulic Structures, Shahid Chamran University of Ahvaz
چکیده [English]

Underflow density currents traveling through density-stratified fluids begin to separate from the bed as they reach areas of similar densities, after which they continue their path as interflows through the surrounding ambient fluid. This point, which is referred to as “separation point” of density currents, acts as the boundary between the underflow and interflow density currents. A density current within a stratified environment is known as intrusive gravity currents (IGC), which travel horizontally at a roughly constant velocity U within the stratified layer after propagation (Nokeset al., 2008). Regarding underflow density currents, efforts have been made by many researchers e.g. Singh, and Shah (1971), Lee, and Yu (1997) and Farrell, and Stefan (1986) in the past decades to determine the location of the plunge point of underflow density currents (which is similar to the separation point in interflow currents) using experimental and theoretical methods based on the Densimetric Froude Number at the plunge point Fp. Although studies have been conducted on interflow density currents, including Kao (1977), Wells, and Nadarajah (2008), An, and Julien (2014) and Zhang et al. (2015). Not any research has been found in the literatures about the height of density current at the point of separation from the bed. Hence, in addition to examining the height variations in density currents at the separation point with respect to changes in hydraulic parameters such as flow rate, density of the flow at the inlet, as well as the bed slope, the present study attempted to derive a relation for prediction of density current height at the point of separation from the bed under different conditions.

کلیدواژه‌ها [English]

  • Interflow density current
  • Separation point
  • Height of current
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