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This study presented an experimental investigation on heat transfer performance of a shell-and-tube heat exchanger with and without circular fins. Particular attention has been paid to the effect of injection flow rate of heat transfer fluid (HTF) on the thermal performance of the heat exchanger. A purposely-designed apparatus was built for experimental observation. Results showed that the application of fins had a great effect on improving phase change heat transfer and the full charging time was significantly reduced. Injection flow rate of HTF was found to have little influence upon the performance of the heat exchanger.

The shell and tube latent heat thermal energy storage systems are widely recognized as one of the most effective ways to store and utilize solar energy due to their high energy density, constant storage/releasing temperature, structural feasibility and rational price. The application of fins is an effective method to enhance heat exchange through extend the heat transfer surface area. However, there existed strong uneven melting behavior including melting fraction, temperature uniformity in a vertical thermal energy storage unit. To improve its uniformity of melting fraction and temperature, this study designed various conditions for fin pitch and positions in a non-uniform pattern to reduce the inhomogeneity for the melting process. Numerical models were established and validated by the experimental measurement conducted in this study. The effects of fin pitch and position on the thermal performance of the melting process were quantified via analyzing the melting front evolution, temperature and velocity distribution, melting rate and temperature uniformity. Results demonstrated that a 62.8% and 34.4% reduction in full melting time and average temperature difference in the phase change material region was separately obtained for the thermal energy storage unit with non-uniformly distributed annular fins, compared to the original case with uniform fins. Besides, the melting rate uniformity was also improved by 84.7%. The non-uniform design on fin position and pitch give a perspective to enriching the design methods for practical application in engineering.

Thermal energy storage has attracted more and more attentions due mainly to its ability of peak load shifting. Shell-and-tube configuration is a typical heat exchanger for thermal energy storage. T ...

Liquid-solid interaction produces a characteristic sound which is different from the sound of bubbly water flows. This paper explores liquid-solid interaction sound (LSIS) synthesis. The resulting LSIS consists of two components: bubble sound and impact sound, which corresponding to liquid-liquid collision and liquid-solid collision, respectively. To improve the quality of LSIS, we propose a novel sound enrichment method called Feature Transfer Synthesis (FTS), which is designed to compensate for the differences between the real-world recording and the synthesized sound. We also greatly resolve the synchronization problem during blending the two components of LSIS through a key frame algorithm with normal force and grid surface. Moreover, a generalized dipole model for sound radiation is performed to estimate the LSIS pressure at a listener position. We illustrate our approach through a series of experiments and a perceptual user study, demonstrating the utility of our LSIS synthesis pipeline in producing realistic sounds at practical computational times.

This paper presents a novel framework to generate the sound of outdoor natural scenes, such as waterfall, ocean, etc. Our method firstly simulates liquid with a grid-based method. Then combined with the movement of liquid, we generate seed-particles which represent bubbles, foams or splashes. Next, we assign each seed-particles a radius with a new radius distribution model. By calculating the bubbles' pressure wave we generate the sound. Experiments demonstrated that our novel framework can efficiently synthesize the sounds for natural scenes.