14:20   PIV/PTV methods and applications V Low Reynolds number propellers under non uniform inflow conditions Sara Montagner, Jacopo Serpieri, Gioacchino Cafiero Abstract: This work investigates the aerodynamic performance of low Reynolds number propellers operating under non-uniform inflow conditions, representative of complex urban environments. Using a WindShaper system, the study examines how gusts and shear flows affect efficiency and wake structure. Future analyses will focus on Particle Image Velocimetry (PIV) measurements to gain deeper insight into the wake dynamics and flow organization. In vitro PIV analysis of flow dynamics in a left ventricle model equipped with a physiological transcatheter mitral valve prosthesis Manuel Zannone, Elena Torta, Daniele Pecchio, Diego Gallo, Umberto Morbiducci Abstract: This study presents an in vitro characterization of intraventricular flow induced by a physiological transcatheter mitral valve prosthesis using two-dimensional Particle Image Velocimetry (PIV). Experiments were conducted in a silicone left ventricle phantom under physiological flow conditions. Phase-averaged velocity fields were analyzed to quantify vortex formation, circulation, and energy dissipation. The results show that the prosthesis generates a stable, clockwise vortex, with peak circulation and total viscous energy dissipation comparable to native valve function. Kinetic energy decomposition reveals that flow is dominated by organized, phase-correlated motion. Future measurements will be conducted on a plane perpendicular to the one presented here. This will enable a more detailed analysis of the three-dimensional structure of the vortex. The Air and Droplet Dynamics of a Soft Mist Inhaler Michael Jehan Pangestu, Bihai Sun, Alireza Heidarian, Vishal Chaugule, Patrick He, Hui Xin Ong, Imco Sibum, Wietze Nijdam, Nicolas Buchmann, Daniela Traini, Julio Soria Abstract: Innovations in inhaler technology have resulted in the development of low-velocity spray devices called soft mist inhalers (SMIs). The SMI is a propellant-free multidose inhaler device that does not suffer from the ‘ballistic effects’ of aerosols associated with other inhaler technologies. This study uses advanced laser-based imaging methodologies to measure the instantaneous 2-component – 2-dimensional (2C-2D) air velocity field using particle image velocimetry (PIV) and the associated 2C-2D water mist droplet velocity field using particle tracking velocimetry (PTV) for the Resyca® Pre-Filled Syringe Inhaler (PFSI) soft mist inhaler (SMI) under typical operating conditions. These high-fidelity measurements provide detailed information of the corresponding air and water mist droplet velocity distributions and their relationship for this SMI. PIV is a non intrusive optical measurement technique used to measure the instantaneous fluid velocity within a measurement volume. The local fluid motion is determined from the cross-correlation of single-exposed image pairs of tracer particles illuminated by two coincident laser sheets produced by a dual-cavity pulsed laser for the two corresponding exposures, where the laser pulses are temporally separated by a small time, ∆t. PTV measures the velocity of individual particles recorded in the image pair by detecting particles in each image and using the velocity measurements from PIV as a predictor to match the corresponding particle from the first to the second image [2]. The structure and relationship between the 2C-2D velocity measurement of the airflow and droplet kinematics aims to provide insights into the design of future inhaler devices. The spatial distribution of the first-order velocity statistics for the airflow and water mists droplets are presented and compared.

end %-->