バイファルケーションを通過するサスペンションの相分離:簡素化されたヘモダイナミックモデル
Science (New York, N.Y.)
|January 31, 1964
まとめ
血流モデルでは,側枝の球体濃度が,主枝の球体濃度より低い. これは主に流れの分布,上流の濃度,および枝の寸法によって影響されています.
科学分野:
- 流体力学 流体力学
- バイオメディカルエンジニアリング
- ヘモダイナミクス (血動力学)
背景:
- 分裂する流れにおける粒子の分布を理解することは,血液の流れのような生物学的システムをモデル化するために不可欠です.
- 以前の研究では,微流体装置における粒子の振る舞いを調査しましたが,マクロモデルでは異なる視点が提供されています.
研究 の 目的:
- バイフォーケーションを通る血流の簡素化されたマクロスコープモデルで中性浮遊球の分布を調査する.
- 側面の枝とメインの枝における球の濃度に影響を与える重要な要因を特定する.
主な方法:
- 中立浮力球の懸浮のシミュレートされたラミナールフローが,幾何学的バイフォーケーションを通過する.
- 分析された球の濃度は,異なる流量条件下で,メインとサイドブランチで測定された.
主要な成果:
- 副支部の球体の濃度は,主支部よりも一貫して低かった.
- 濃度差は主に2つの分岐間の排出の比率と相関していた.
- アップストリーム集中と支店の大きさも,球球分布に大きな影響を及ぼしていることが示された.
結論:
- 簡素化されたバイフォーケーションモデルは,懸浮粒子に対する好ましい流れ分布を効果的に実証しています.
- 流れの分割比,上流の濃度,および分岐幾何学は,血液流動の動態に関連した,分岐する流れにおける粒子分割の決定的な決定因子です.
関連する概念動画
01:07Laminar and Turbulent Flow
Fluid dynamics is the study of fluids in motion. Velocity vectors are often used to illustrate fluid motion in applications like meteorology. For example, wind—the fluid motion of air in the atmosphere—can be represented by vectors indicating the speed and direction of the wind at any given point on a map. Another method for representing fluid motion is a streamline. A streamline represents the path of a small volume of fluid as it flows. When the flow pattern changes with time, the streamlines...
01:28Navier–Stokes Equations
For incompressible Newtonian fluids, where density remains constant, stresses show a linear relationship with the deformation rate, defined by normal and shear stresses. Normal stresses depend on the pressure exerted on the fluid and the rate of deformation in specific directions, which determines how fluid flows under varying pressures. Shear stresses, on the other hand, act tangentially across fluid layers. They explain how adjacent fluid layers slide relative to one another, connecting...
01:17Steady, Laminar Flow Between Parallel Plates
Understanding steady, laminar flow between parallel plates is essential for analyzing and designing flow in narrow rectangular channels, commonly found in various water conveyance and drainage systems. The Navier-Stokes equations govern fluid motion and are generally challenging to solve due to their nonlinearity. However, simplifications are possible in certain cases, like the steady laminar flow between parallel plates. For this scenario, we assume steady, incompressible, laminar flow.
01:22Couette Flow
Couette flow represents the flow of fluid between two parallel plates, with one plate fixed and the other moving with a constant velocity. This configuration allows for a simplified analysis using the Navier-Stokes equations, which govern fluid motion under conditions of viscosity and incompressibility. For Couette flow, the assumptions include a steady, laminar, incompressible flow with a zero-pressure gradient in the flow direction. This flow type is beneficial for understanding shear-driven...
01:30Typical Model Studies
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
01:21Design Example: Creating a Hydraulic Model of a Dam Spillway
Scaled hydraulic models of dam spillways provide a practical way to replicate and study the intricate flow dynamics of these structures. Often built to a 1:15 ratio, these models allow for observing critical water behavior, such as velocity distribution, flow patterns, and energy dissipation.