A method to extract turbulent statistics from three-dimensional (3D) PIV measurements via ensemble averaging is presented. The proposed technique a 3D extension of the particle tracking velocimetry methods, which consist in summing distributions velocity vectors calculated on low image density samples and then statistical moments within sub-volumes, with size sub-volume depending desired number particles available snapshots.

The present research focuses on the experimental investigation of effectiveness synthetic jet actuation a pair counter-rotating vortices generated by an unswept, low aspect ratio, squared-tipped wing in order to preserve mutual induction during their evolution. is actuated at Crow and Widnall's instability frequencies (F+=0.071,0.55) fixed momentum coefficient Cμ=0.2% with goal reducing vortex strength induced circumferential velocity. effect exit section area, thus characteristic velocity,...

The application of deep reinforcement learning (DRL) to train an agent capable control laws for pulsed jets manipulate the wake a bluff body is presented and discussed. work has been performed experimentally at value Reynolds number Re∼105 adopting single-step approach training agent. Two main aspects are targeted: first, dimension state, allowing us draw conclusions on its effect neural network; second, capability learn optimal strategies aimed maximizing more complex tasks identified with...

We investigate experimentally the effects of micro-grooves on development a zero pressure gradient turbulent boundary layer at two different values friction Reynolds number. consider both well-known streamwise aligned riblets as well wavy riblets, characterized by sinusoidal pattern in mean flow direction. Previous investigations authors showed that yield larger drag reduction with respect to ones. perform new particle image velocimetry experiments wall-parallel planes get insights into...

Phase-averaging is a fundamental approach for investigating periodic and non-stationary phenomena. In fluid dynamics, these can be generated by rotating blades such as propellers/turbines or pulsed jets. Traditional phase-averaging approaches often rely on synchronized data acquisition systems, which might require high-speed cameras, light sources, precise delay generators encoders, making them expensive sometimes unfeasible. This work proposes an posteriori data-driven that reconstructs...

Abstract We present an experimental setup to perform time-resolved convective heat transfer measurements in a turbulent channel flow with air as the working fluid. employ heated thin foil coupled high-speed infrared thermography. The measurement technique is challenged by thermal inertia of foil, high frequency fluctuations, and noise camera. discuss detail advantages drawbacks all design choices that were made, thereby providing successful implementation strategy obtain high-quality data....

We study the self-similarity and dissipation scalings of a turbulent planar jet theoretically implied mean flow scalings. Unlike wakes where such studies have already been carried out (Dairay et al. 2015; Obligado 2016), this is boundary- free shear local Reynolds number increases with distance from inlet. The Townsend-George theory revised by Dairay (2015) applied to jets. Only few profiles need be self-similar in theory. self- similarity flow, turbulence dissipation, kinetic energy stress...

Abstract Thyroid cancer is not very common, accounting for 1–2% of all cancers, with a population incidence about 0.004%. Currently, the ability to discriminate between follicular adenoma and carcinoma represents major challenge in preclinical diagnosis thyroid proliferative lesions. Better discrimination two would help avoid unnecessary thyroidectomy save valuable resources. Over years, galectin‐3 (Gal‐3) has been proposed as diagnostic marker varied success. In this paper, we used...

Fractal grids (FGs) have been recently an object of numerous investigations due to the interesting capability generating turbulence at multiple scales, thus paving way tune mixing and scalar transport. The flow field topology a turbulent air jet equipped with square FG is investigated by means planar volumetric particle image velocimetry. comparison well-known features round without generators also presented. Reynolds number based on nozzle exit section diameter for all experiments set about...

The investigation focuses on the forcing of a fully developed turbulent channel flow through linear array synthetic jets injected tangentially to wall and orthogonal mean direction. Forcing configurations are varied by differently combining number actuated working in an opposing blowing–suction configuration. Instantaneous shear stress streamwise velocity fluctuations evidence drag reductions as well turbulence attenuation up 20%. effects persistent at least 150 half-channel height...

We address the important point of proportionality between longitudinal integral lengthscale (L) and characteristic mean flow width (δ) using experimental data an axisymmetric wake a turbulent planar jet. This is fundamental hypothesis when deriving self-similar scaling laws in free shear flow. show that L/δ indeed constant, at least range streamwise distances 15 50 times inlet dimension. revisit turbulence closure models such as Prandtl mixing length eddy viscosity light non-equilibrium...

This paper presents a numerical investigation of the effects moving ground and rotating wheels on turbulent flow around 1/10 scaled square-back van model. A comprehensive comparison among partially averaged Navier–Stokes (PANS), large eddy simulation (LES) particle image velocimetry (PIV) involving aerodynamic drag, wake topology, velocity Reynolds stress profiles in region is conducted. The proper orthogonal decomposition (POD) fast Fourier transform (FFT) are applied to shear layers...

AbstractAbstractLead accumulation in the moss Funaria hygrometrica was investigated using experimentally supplied solutions at different concentrations (10−2-10−4 M) and for periods from 1 to 30 d. Lead qualitatively quantitatively measured by X-ray SEM microanalysis tissues. is preferentially accumulated some tissues (gametophyte hydroids, sporophyte hydroids foot level, transfer cells) never reaches upper part of seta or capsule. At cell lead localization assessed TEM microanalysis....

The length scale which, combined with the fluid's kinematic viscosity $\ensuremath{\nu}$, defines local average speed of turbulent-nonturbulent interface has been postulated to be smallest (Kolmogorov) $\ensuremath{\eta}$ turbulence Corrsin and Kistler, [NACA Report No. 1244, 1955, p. 1033.]. This is indeed case when dissipation rate obeys Kolmogorov equilibrium cascade scaling, but in presence nonequilibrium scaling scales as $\ensuremath{\nu}/\ensuremath{\lambda}$, instead...