Computational Modeling of Turbulent Velocity Structures for an Open Channel Flow Using Karhunen–loéve Expansion
نویسنده
چکیده
This paper develops an analytical two-part covariance kernel from velocity correlations across a two-dimensional (vertical and flow directions) Particle Image Velocimetry (PIV) flow field. This will form the basis of a model of wave action in flood water that includes the underlying turbulence velocity field using Karhunen–Loéve (KL) expansion. The PIV data was from the supercritical flow area immediately upstream of an undular hydraulic jump. This paper derives a one-dimensional solution for the associated integral equations. It also discusses a relationship between the two parts of the kernel and the turbulent production and turbulent dissipation.
منابع مشابه
On Coherent Structures of Turbulent Open-channel Flow Above a Rough Bed
Present study examines turbulent structures of a rough bed open-channel flow in the context of deterministic approach. Instantaneous velocity field is measured in different hydraulic conditions using two dimensional Particle Image Velocimetry (PIV) in vertical plane and Stereoscopic PIV in horizontal plane. Different techniques and quantities such as swirl strength, two-point and cross-correlat...
متن کاملAnalysis of the Characteristics, Physical Concepts and Entropy Generation in a Turbulent Channel Flow Using Vortex Blob Method
In this paper, using vortex blob method (VBM), turbulent flow in a channel is studied and physical concepts of turbulence are obtained and discussed. At first, time-averaged velocities, and , and then their fluctuations are calculated. To clarify turbulence structures, velocity fluctuations and are plotted. It is observed that turbulence structures occupy different positions and move with con...
متن کاملAssessment of Turbulent Models in Computation of Strongly Curved Open Channel Flows
Several rigorous turbulent models have been developed in the past years and it can be seen that more research is needed to reach a better understanding of their generality and precision by verifying their applications for distinct hydraulic phenomena; under certain assumptions. This survey evaluates the performance of Standard k-ε, Realizable k-ε, RNG k-ε, k-ω and RSM models in predicting flow ...
متن کاملComputational fluid dynamics study and GA modeling approach of the bend angle effect on thermal-hydraulic characteristics in zigzag channels
In the study, the thermal-hydraulic performance of the zigzag channels with circular cross-section was analyzed by Computational Fluid Dynamics (CFD). The standard K-Ꜫ turbulent scalable wall functions were used for modeling. The wall temperature was assumed constant 353 K and water was used as the working fluid. The zigzag serpentine channels with bend angles of 5 - 45° were studied for turbul...
متن کاملImpact of the Confluence Angle on Flow Field and Flowmeter Accuracy in Open Channel Junctions
Open channel junction is one of the most common hydraulic structures that are used in various practical situations such as sewer, drainage, and flood control systems. Knowing the fluid flow behavior, is one of the most important topics in designing the efficient open channel junctions. The complexity and deviation of flow in the junction’s zone disrupts the proper functioning of the flowmeter d...
متن کامل