The output signal of a Kovasznay type vorticity probe is in first-order approximation proportional to the longitudinal component of the vorticity omegax= partial differentialw/ partial differentialy- partial differentialv/ partial differentialz and does not depend on the two transverse components of the flow velocity v, w. An experimental investigation of the influence of all three fluctuating velocity components on the longitudinal vorticity signal showed that their influence may not be neglected. The error in the probe response caused by the longitudinal component of the flow velocity was easily corrected using the instantaneous longitudinal velocity component and digital measuring techniques. On the other hand, the error caused by the two transverse velocity components could not be corrected. The contamination of the vorticity signal produced by the two transverse velocity components has been calculated by considering first- and second-order terms. The agreement between the calculations and experimental measurements is good. It is concluded that in a turbulent flow field this probe cannot be used without the simultaneous knowledge of the instantaneous transverse velocity components.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/1.1135917 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Shear wave elastography primer for the abdominal radiologist.
Abdom Radiol (NY)
January 2025
AGH University of Krakow, Krakow, Poland.
Purpose: Shear wave elastography (SWE) provides a means for adding information about the mechanical properties of tissues to a diagnostic ultrasound examination. It is important to understand the physics and methods by which the measurements are made to aid interpretation of the results as they relate to disease processes.
Methods: The components of how ultrasound is used to generate shear waves and make measurements of the induced motion are reviewed.
A review of recent advancements in the impact response of fiber metal laminates.
Heliyon
January 2025
Natural Composites Research Group Lab, Department of Materials and Production Engineering, The Sirindhorn International Thai-German School of Engineering (TGGS), King Mongkut's University of Technology North Bangkok (KMUTNB), Bangkok, 10800, Thailand.
Fiber metal laminates (FMLs) have garnered significant attention due to their exceptional impact resistance, making them attractive for various structural applications. This review presents recent advancements in understanding the impact behavior of FMLs under low- and high-velocity impact scenarios. Low-velocity impacts, commonly encountered during manufacturing, handling, and tool drops, are discussed, with a focus on damage mechanisms, energy absorption capabilities, and influential factors such as impactor geometry and boundary conditions.
View Article and Find Full Text PDFEnergy-based modelling of single actin filament polymerization using bond graphs.
J R Soc Interface
January 2025
Department of Biomedical Engineering, Faculty of Engineering & Information Technology, University of Melbourne, Melbourne, Victoria 3010, Australia.
Bond graphs provide an energy-based methodology for modelling complex systems hierarchically; at the moment, the method allows biological systems with both chemical and electrical subsystems to be modelled. Herein, the bond graph approach is extended to include chemomechanical transduction thus extending the range of biological systems to be modelled. Actin filament polymerization and force generation is used as an example of chemomechanical transduction, and it is shown that the (transformer) bond graph component provides a practical, and conceptually simple, alternative to the Brownian ratchet approach of Peskin, Odell, Oster and Mogilner.
View Article and Find Full Text PDFOrientation selectivity properties for the affine Gaussian derivative and the affine Gabor models for visual receptive fields.
J Comput Neurosci
January 2025
Computational Brain Science Lab, Division of Computational Science and Technology, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
This paper presents an in-depth theoretical analysis of the orientation selectivity properties of simple cells and complex cells, that can be well modelled by the generalized Gaussian derivative model for visual receptive fields, with the purely spatial component of the receptive fields determined by oriented affine Gaussian derivatives for different orders of spatial differentiation. A detailed mathematical analysis is presented for the three different cases of either: (i) purely spatial receptive fields, (ii) space-time separable spatio-temporal receptive fields and (iii) velocity-adapted spatio-temporal receptive fields. Closed-form theoretical expressions for the orientation selectivity curves for idealized models of simple and complex cells are derived for all these main cases, and it is shown that the orientation selectivity of the receptive fields becomes more narrow, as a scale parameter ratio , defined as the ratio between the scale parameters in the directions perpendicular to vs.
View Article and Find Full Text PDFChiral Locomotion Transitions of an Active Gel and Their Chemomechanical Origin.
J Am Chem Soc
January 2025
College of Chemical Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu, P.R. China.
Transitions between chiral rotational locomotion modes occur in a variety of active individuals and populations, such as sidewinders, self-propelled chiral droplets, and dense bacterial suspensions. Despite recent progress in the study of active matter, general principles governing rotational chiral transition remain elusive. Here, we study, experimentally and theoretically, rotational locomotion and its chiral transition in a 2D polyacrylamide (PAAm)-based BZ gel driven by Belousov-Zhabotinsky reaction-diffusion waves.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!