This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

Introduction to the Finite Element Method

Thermal energy storage technologies and systems for concentrating solar power plants

Pool boiling characteristics of nano-fluids

Thermal energy storage has recently attracted increasing interest related to thermal applications such as space and water heating, waste heat utilization, cooling and air-conditioning. Energy storage is essential whenever there is a mismatch between the supply and consumption of energy. Use of phase change material (PCM) capsules assembled as a packed bed is one of the important methods that has been proposed to achieve the objective of high storage density with higher efficiency. A proper designing of the thermal energy storage systems using PCMs requires quantitative information about heat transfer and phase change processes in PCM. This paper reviews the development of available latent heat thermal energy storage technologies. The different aspects of storage such as material, encapsulation, heat transfer, applications and new PCM technology innovation have been carried out.

Heat transfer characteristics of thermal energy storage system using PCM capsules: A review

An overview of thermal energy storage systems

https://www.tpbin.com/Uploads/Subjects/409a6649-39ac-432c-8615-88b8953d3b14.pdf

Effect of diameter on two-phase pressure drop in narrow tubes

The effect of tube diameter on two-phase flow patterns was investigated in circular tubes with inner diameters of 0.6, 1.2, 1.7, 2.6, and 3.4 mm using air and water. The gas and liquid superficial velocity ranges were 0.01–50 and 0.01–3 m/s, respectively. The gas and liquid flow rates were measured and the two-phase flow pattern images were recorded using high-speed CMOS camera. The flow patterns observed were dispersed bubbly, bubbly, slug, slug-annular, wavy-annular, stratified, and annular flows. These flow patterns were not observed in all the test diameters, but were found to be unique to particular tube diameters, confirming the effect of tube diameter on the flow pattern. The data obtained were compared to existing experimental data and flow regime transition maps which show generally reasonable overall agreement at the larger diameters, but significant differences were observed with the smaller diameter tubes.



On a analyse l'effet du diametre des tubes dans des modeles d'ecoulement biphase dans des tubes circulaires avec des diametres internes de 0,6, 1,2, 1,7, 2,6 et 3,4 mm en utilisant de l'air et de l'eau. Les ecarts de vitesse superficielle de gaz et de liquide etaient de 0,01–50 m/s et 0,01–3 m/s respectivement. Les debits de gaz et de liquide ont ete mesures et les images des modeles d'ecoulement biphase ont ete enregistrees a l'aide d'un appareil photo CMOS haute vitesse. Les modeles d'ecoulement observes etaient l'ecoulement a bulles, a bulles, en piston, en piston annulaire, ondule annulaire, stratifie et annulaire. Ces modeles d'ecoulement n'ont pas ete observes dans tous les parametres d'essai, mais on a constate qu'ils etaient uniques aux diametres de tubes particuliers, ce qui confirme l'effet du diametre des tubes sur le modele d'ecoulement. Les donnees obtenues ont ete comparees aux donnees experimentales existantes et aux cartes de transition des regimes d'ecoulement qui demontrent un accord global raisonnable de facon generale aux parametres plus grands, mais des differences importantes ont ete observees dans les tubes aux diametres plus petits.

Effect of tube diameter on two-phase flow patterns in mini tubes

Heatline analysis of heat recovery and thermal transport in materials confined within triangular cavities

Two phase flow regime identification using infrared sensor and volume of fluids method

Experiments were conducted to study the effect of tube inclination on nucleate pool boiling heat transfer for different tube diameters and surface roughness values. The results show that as the tube is tilted from the vertical to the horizontal, the temperatures at the top and bottom (with respect to circumference) increase and decrease, respectively. The increase and decrease is such that they almost compensate for each other, resulting in very little variation of the average heat transfer coefficient with tube inclination. The increase in bubble sliding length at the bottom wall and decrease in bubble sliding length at the top wall are thought to be the reasons for this behaviour. Experiments have been conducted with water, ethanol and acetone at atmospheric pressure, to confirm similar effects of inclination irrespective of fluid property.

A.R. Balakrishnan

Papers

Effect of diameter on two-phase pressure drop in narrow tubes

Effect of tube diameter on two-phase flow patterns in mini tubes

Heatline analysis of heat recovery and thermal transport in materials confined within triangular cavities

Two phase flow regime identification using infrared sensor and volume of fluids method

Experimental studies on the effect of tube inclination on nucleate pool boiling