Jacopo Buongiorno

Bio: Jacopo Buongiorno is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: Boiling & Nanofluid. The author has an hindex of 40, co-authored 170 publications receiving 12125 citations. Previous affiliations of Jacopo Buongiorno include Electric Power Research Institute & Tokyo Electric Power Company.

Medium-Power Lead-Alloy Fast Reactor Balance-of-Plant Options

Abstract: Proper selection of the power conversion cycle is a very important step in the design of a nuclear reactor. Due to the higher core outlet temperature (˜550°C) compared to that of light water reacto...

Measurement of nucleation site density, bubble departure diameter and frequency in pool boiling of water using high-speed infrared and optical cameras

Abstract: A high-speed video and IR thermometry based technique has been used to obtain time and space resolved information on bubble nucleation and boiling heat transfer. This approach provides a fundamental and systematic method for investigating nucleate boiling in a very detailed fashion. Data on bubble departure diameter and frequency, growth and wait times, and nucleation site density are measured with relative ease. The data have been compared to the traditional decades-old and poorly-validated nucleate-boiling models and correlations. The agreement between the data and the models is relatively good. This study also shows that new insights into boiling heat transfer mechanisms can be obtained with the present technique. For example, our data and analysis suggest that a large contribution to bubble growth comes from heat transfer through the superheated liquid layer in addition to micro layer evaporation. (author)

Surface Modifications Using Nanofluids for Nucleate Boiling Heat Transfer and CHF Enhancements

Abstract: Colloidal dispersions of nanoparticles, also known as nanofluids, have shown to result in significant Critical Heat Flux (CHF) enhancement. The CHF enhancement mechanism in nanofluids is due to the buildup of a layer of nanoparticles which occurs upon boiling. Some studies have shown that this layer may also lead to increase in nucleate boiling heat transfer. Therefore, this paper discusses how key surface parameters such as surface wettability and surface roughness can be manipulated and optimized by coating nanoparticles in colloidal dispersions onto the desired surface, to enhance the nucleate boiling heat transfer and CHF.Copyright © 2008 by ASME

Heavy-Metal Aerosol Transport in a Lead-Bismuth-Cooled Fast Reactor with In-Vessel Direct-Contact Steam Generation

Abstract: The choice of lead or lead alloys (Pb-Bi) as the coolant of a fast reactor offers the potential for enhanced safety and reliability due to their benign physical and chemical characteristics. In an effort to assess this class of coolants in advanced nuclear systems of the next generation, an innovative fast reactor concept that eliminates the need for steam generators and main coolant pumps and thus offers capital and operating cost reduction was explored. The working steam is generated by direct-contact vaporization of water by liquid metal in the chimney above the core and is then sent directly to the turbine. The presence of a lighter fluid in the chimney substantially enhances the natural circulation of the Pb-Bi within the reactor pool. A key technical issue of this reactor concept is the consequences of Pb-Bi aerosol generation within the vessel, its transport within the power cycle components and impact on the design and operation of the turbine.Generation, transport, and deposition of Pb-Bi aerosols were modeled. It was found that the utilization of a suitable chevron steam separator design reduces the heavy-liquid metal transported to the steam lines by about three orders of magnitude. Nevertheless, the residual Pb-Bi ({approx}0.003 kg/s) ismore » predicted to be sufficient to cause embrittlement of the turbine blades if conventional materials are used and the plant is to operate for 40 yr. Four solutions to this problem were assessed and found potentially viable from a technical standpoint: blade coating, employment of alternative materials, electrostatic precipitation, and oxidation of the Pb-Bi droplets.« less

Climate change 2014 - Mitigation of climate change

Abstract: The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

World energy outlook

Abstract: This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

A review on nanofluids: preparation, stability mechanisms, and applications

Abstract: Nanofluids, the fluid suspensions of nanomaterials, have shown many interesting properties, and the distinctive features offer unprecedented potential for many applications. This paper summarizes the recent progress on the study of nanofluids, such as the preparation methods, the evaluation methods for the stability of nanofluids, and the ways to enhance the stability for nanofluids, the stability mechanisms of nanofluids, and presents the broad range of current and future applications in various fields including energy and mechanical and biomedical fields. At last, the paper identifies the opportunities for future research.