Annular finned tube bundles are commonly used for heat recovery systems. Nowadays, systems important in the energy economy. Cross-flow exchangers, one of exchanger types suitable waste fins utilized cross-flow exchangers a long time. In this study, two annular fin geometry, namely solid and serrated fins, were studied numerically exchangers. All numerical analyses performed ANSYA-FLUENT program...

An experimental and numerical analysis of a low-angle annular expander nozzle is presented to observe the variance in shock structure within the flow field. A RANS-based axisymmetric numerical model was used to evaluate flow characteristics and the model validated using experimental pressure readings and schlieren images. Results were compared with an equivalent convergingdiverging nozzle to de...

Isothermal and non-isothermal LES (Large Eddy Simulation) has been carried out to fully reproduce the characteristics of the flow field in eccentric annular channels, and rod bundles. The numerical approach is based upon boundary fitted coordinates and a fractional step algorithm; a dynamic Sub Grid Scale (SGS) model suited for this numerical environment has been implemented and tested for both...

BACKGROUND This study aimed to investigate the distribution of conventional Doppler measurements, pulsed wave tissue Doppler imaging (pwTDI)- and color tissue Doppler imaging-derived velocities, by age and sex in a healthy population. METHODS AND RESULTS Longitudinal tissue Doppler velocities were determined in 1266 healthy individuals from standard apical 4- and 2-chamber views. By the pwTDI...

Combined radiation and natural convection within the annular region of two infinitely long horizontal concentric cylinders are investigated numerically in this research. Radial and tangential radiation effects ate considered using Milne-Eddington approximation for a two-dimensional radiative transfer. The basic conservation equations are discretized with the finite volume method and SIMPLER alg...

In this paper, a modified two-fluid model has been adopted to simulate the process of upward vertical subcooled flow boiling of refrigerant R-113 in a vertical annular channel at low pressure. The modified model considers temperature dependent properties and saturation temperature variation and was validated against a number of published low-pressure subcooled boiling experiments. The results s...

The "North Atlantic Oscillation (NAO)" as defined in Walker and Bliss (1932) has been traditionally viewed as a teleconnection pattern with 'centers of action' in the Atlantic sector. In contrast, the "zonal index cycle", as articulated by Namias (1950), involves the interactions between a fundamentally zonally symmetric or 'annular’ mode and the eddies. The perceived dynamical significance of ...

Flow boiling of HFE 7000 in five parallel microchannels of 222 m hydraulic diameter, each containing a single row of 24 in-line 100 m pin fins, was investigated. High speed photography revealed the dominant flow patterns, namely, the bubbly flow, the multiple flow, and the wavy-annular flow. The interaction of the bubble with the pin fins during nucleate boiling from G 350 kg /m2 s to G 827 kg ...