We describe a scheme of molecular tagging velocimetry in air in which nitric oxide (NO) molecules are created out of O2 and N2 molecules in the focus of a strong laser beam. The NO molecules are visualized a while later by laser-induced fluorescence. The precision of the molecular tagging velocimetry of gas flows is affected by the gradual blurring of the written patterns through molecular diff...

Laser Doppler Velocimetry (LDV) has been employed to determine pseudo-turbulence characteristics of the flow field around bubble train forming in non-Newtonian caboxymethylcellulose (CMC) aqueous solution at low gas flow rate condition. The Reynolds stress and turbulent intensity of the liquid were investigated by means of Reynolds time-averaged method. The experimental results show that ax...

This paper presents preliminary velocity and scalar measurements of low swirl intensity jets in air. Swirling jets were generated using a micro-injector swirl generator. Velocity fields of the jets were obtained using Multi-grid Cross Correlation Digital Particle Image Velocimetry. Initial flow visualizations were performed using planar laser induced fluorescence with acetone as tracer species.

This study presents preliminary results on the application of combined Particle Image Velocimetry – Laser Induced Fluorescence measurements to characterize flow and mixing processes of stratified flows at laboratory scale. Laboratory experiments were conducted with two different bottom configuration and two hydraulic submergences showing the influence of these aspects in the exchange flows.

By employing a combination of optical heterodyne and linear frequency modulation techniques and utilizing state-of-the-art fiber optic technologies, highly efficient, compact and reliable lidar suitable for operation in a space environment is being developed. OCIS Codes: (280.3640) Lidar; (280.3340) Laser Doppler Velocimetry

For longtime, the investigation of flow regimes has been achieved using fluorescent particles or anisotropic reflective particles. Fluorescent particles are suitable for open flows (Van Dyke, 1982) such as flows in channels (Peerhossaini et al., 1988) or flows behind a cylinder (to visualize Benard-von Karman street) (Provansal et al., 1986; Mutabazi et al., 2006). For closed flows such as flow...

This study investigates (1) the effect of modifying the design of a dry powder inhaler on the device performance, and (2) which design features significantly contribute to overall inhaler performance. Computational Fluid Dynamics (CFD) analysis was performed to determine how the flowfield generated in an Aerolizer at 60 l min(-1) varied when the inhaler grid and mouthpiece were modified. The co...

In this work, we present the excitation/emission strategy, experimental setup, and results of an implementation of krypton tagging velocimetry (KTV). KTV is performed as follows: (i) seed a base flow with krypton; (ii) photosynthesize metastable krypton atoms with a frequency-doubled dye laser to form the tagged tracer; (iii) record the translation of the tagged metastable krypton by imaging th...