OBJECTIVE During extracorporeal circulation design and orientation of aortic cannulae tips mainly determine flow pattern in the aortic arch and arch vessels which is the objective of this in vitro study, comparing single versus multiple stream cannulae. METHODS In an aortic arch glass model, jet streams of 21-24 French aortic cannulae which were inserted in the ascending aorta were directed a...

Edney type IV and type VII shock-shock interactions are complex hypersonic flow phenomena. They are characterized by a supersonic jet which reaches far into the flow field. An experimental investigation of the inner jet structure is difficult, especially in cases where the jet is subject to high-frequency unsteady movements. The present paper provides insight into the jet structure by means of ...

Nano-size maghemite (γ-Fe2O3) particles were prepared in one step using ultrasound radiation. The obtained nanoparticles were characterized by SEM, TEM , XRD, FTIR, and VSM. The results revealed that the synthesized nanoparticles were spherical, mono-dispersed and uniform. Furthermore, the crystalline structure of nanoparticles endorsed by X-ray diffraction study. The FTIR spectra have provided...

Introduction Jet pumps are static components that can be used in closed-loop, traveling wave thermoacoustic devices to suppress a time-averaged mass flux (Gedeon streaming) that can exist [2]. The minimization of convective heat transport caused by this mass flux is of vital importance due to the detrimental effect it has on the device’s efficiency. Jet pumps have an asymmetric shape, resulting...

Background Patients with aortic dilation often present an eccentric transvalvular flow jet. The angle of the flow jet from the aorta centerline, or the flow jet angle (FJA), has been reported as a risk factor in bicuspid aortic valve patients [1]. In recent studies we introduced a the jet shear layer detection (JSLD) method for the automated characterization of transvalvular flow structure acro...

A computational fluid dynamics model is used to predict the oscillatory flow through tapered cylindrical tube sections (jet pumps). The asymmetric shape of jet pumps results in a time-averaged pressure drop that can be used to suppress Gedeon streaming in closed-loop thermoacoustic devices. However, previous work has shown that flow separation in the diverging flow direction counteracts the tim...

We studied surface adherence and its effects on color Doppler jet areas and color encoding in an in vitro model with a noncompliant receiving chamber into which a steady flow jet was directed parallel to either a straight or a curved surface adjacent to and 4 mm away from the inflow orifice (1.50 mm2) with the control condition being a free jet matched for flow rates and driving pressures. Jets...

The paper describes the results of numerical study of flow in the exhaust jet of turbofan engine CFM 56-3. Influence of computational domain decomposition, grid refinement and flow model on the jet flow field is discussed. Special attention is payed to simulation of nucleation and condensation processes in the exhaust jet. Growth of water clusters in the jet and cluster distribution in size are...

The transitional Reynolds numbers for different patterns are available and a proposed transitional map is also provided in this paper. The transition of falling-films on flat tubes is studied in this work. Water and ethylene glycol are used as working fluids, for falling-film experiments conducted under adiabatic conditions, without an imposed vapor flow. The flow patterns are recorded using a ...