This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow con...This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.展开更多
在描述气泡聚并的碰撞筒(Collision Tube)理论中,气泡沿碰撞方向的横截面积及其所携带的湍动能是决定碰撞速率的两个关键点。在气液鼓泡流动中,随着气泡体积增大,气泡形状由球形向椭球形、球帽形转变,其相应的投影面积也发生变化。由于...在描述气泡聚并的碰撞筒(Collision Tube)理论中,气泡沿碰撞方向的横截面积及其所携带的湍动能是决定碰撞速率的两个关键点。在气液鼓泡流动中,随着气泡体积增大,气泡形状由球形向椭球形、球帽形转变,其相应的投影面积也发生变化。由于气泡对液相的强烈作用,液相湍流中剪切湍流和由气泡尾涡诱导的湍流涡漩二者共存,并且在不同的时空范围内对即将发生碰撞的气泡所携带的湍动能产生影响。针对Prince and Blanch聚并模型中的球形气泡假定和剪切湍流作用,本研究建立了考虑气泡形状和气泡诱导湍流的气泡聚并过程动力学模型,并基于群体平衡模型进行了模拟。研究结果表明,在气泡聚并模型中考虑气泡形状变化、气泡诱导湍流和剪切湍流的共同作用,能够准确捕捉气液鼓泡流动中气泡的尺寸分布特征,并且能够进一步影响气液两相的动力学特性预测结果。展开更多
基金the Scientific Research Projects Unit of Erciyes University under contract no:FDS-2022-11532 and FOA-2025-14773.
文摘This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.
文摘在描述气泡聚并的碰撞筒(Collision Tube)理论中,气泡沿碰撞方向的横截面积及其所携带的湍动能是决定碰撞速率的两个关键点。在气液鼓泡流动中,随着气泡体积增大,气泡形状由球形向椭球形、球帽形转变,其相应的投影面积也发生变化。由于气泡对液相的强烈作用,液相湍流中剪切湍流和由气泡尾涡诱导的湍流涡漩二者共存,并且在不同的时空范围内对即将发生碰撞的气泡所携带的湍动能产生影响。针对Prince and Blanch聚并模型中的球形气泡假定和剪切湍流作用,本研究建立了考虑气泡形状和气泡诱导湍流的气泡聚并过程动力学模型,并基于群体平衡模型进行了模拟。研究结果表明,在气泡聚并模型中考虑气泡形状变化、气泡诱导湍流和剪切湍流的共同作用,能够准确捕捉气液鼓泡流动中气泡的尺寸分布特征,并且能够进一步影响气液两相的动力学特性预测结果。
