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Author

Bo Ruan

Other affiliations: Zhejiang University
Bio: Bo Ruan is an academic researcher from Dalian University of Technology. The author has contributed to research in topics: Heat transfer & Supercritical fluid. The author has an hindex of 8, co-authored 12 publications receiving 206 citations. Previous affiliations of Bo Ruan include Zhejiang University.

Papers
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Journal ArticleDOI
TL;DR: In this article, the standard k-e turbulence model with an enhanced wall treatment works well for supercritical-pressure heat transfer of hydrocarbon fuels without buoyancy effect, both with and without fuel pyrolysis, but the main weakness of the model is in the inlet region, where it tends to under-predict the wall temperature at a low inlet Reynolds number.

52 citations

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TL;DR: In this article, a new numerical method, Element Differential Method (EDM), is proposed for solving general heat conduction problems with variable conductivity and heat source subjected to various boundary conditions.

48 citations

Journal ArticleDOI
TL;DR: In this paper, a new numerical method, Element Differential Method (EDM), is proposed for solving general thermal-mechanical problems, which is the direct differentiation of the shape functions of Lagrange isoparametric elements used to characterize the geometry and physical variables.
Abstract: SUMMARY In this paper, a new numerical method, Element Differential Method (EDM), is proposed for solving general thermal-mechanical problems. The key point of the method is the direct differentiation of the shape functions of Lagrange isoparametric elements used to characterize the geometry and physical variables. A set of analytical expressions for computing the first and second order partial derivatives of the shape functions with respect to global coordinates are derived. Based on these expressions, a new collocation method is proposed for establishing the system of equations, in which the equilibrium equations are collocated at nodes inside elements, and the traction equilibrium equations are collocated at interface nodes between elements and outer surface nodes of the problem. Attributed to the use of the Lagrange elements which can guarantee the variation of physical variables consistent through all elemental nodes, EDM has higher stability than the traditional collocation method. The other main features of EDM are that no mathematical or mechanical principles are required to set up the system of equations and no integrals are involved to form the coefficients of the system. A number of numerical examples of two- and three-dimensional problems are given to demonstrate the correctness and efficiency of the proposed method.

44 citations

Journal ArticleDOI
Hua Meng1, Bo Ruan1
TL;DR: A comprehensive review of recent research progress on PEM fuel cell cold-start phenomena has been presented in this article, where the effects of many key parameters, including the water vapor concentration in the cathode gas channel, the initial membrane water content, the operating current density, and the startup cell temperature, have been carefully examined to elucidate the fundamental physics of PEM Fuel Cell cold starts.
Abstract: Successful startup from subfreezing temperatures is a prerequisite for PEM fuel cell commercialization. In this paper, a comprehensive review of recent research progress on PEM fuel cell cold-start phenomena has been presented. Experimental studies are first briefly summarized. A transient multiphase multi-dimensional PEM fuel cell model, accommodating ice formation and temperature variation, is introduced. Numerical results from both isothermal operations and non-isothermal self-starts at subfreezing startup temperatures have been analyzed. The effects of many key parameters, including the water vapor concentration in the cathode gas channel, the initial membrane water content, the operating current density, and the startup cell temperature, on PEM fuel cell cold-start behaviors have been carefully examined to elucidate the fundamental physics of PEM fuel cell cold starts. Copyright © 2010 John Wiley & Sons, Ltd.

41 citations

Hua Meng1, Bo Ruan1
01 Jan 2011
TL;DR: A comprehensive review of recent research progress on PEM fuel cell cold-start phenomena has been presented in this article, where the effects of many key parameters, including the water vapor concentration in the cathode gas channel, the initial membrane water content, the operating current density, and the startup cell temperature, have been carefully examined to elucidate the fundamental physics of PEM Fuel Cell cold starts.
Abstract: Successful startup from subfreezing temperatures is a prerequisite for PEM fuel cell commercialization. In this paper, a comprehensive review of recent research progress on PEM fuel cell cold-start phenomena has been presented. Experimental studies are first briefly summarized. A transient multiphase multi-dimensional PEM fuel cell model, accommodating ice formation and temperature variation, is introduced. Numerical results from both isothermal operations and non-isothermal self-starts at subfreezing startup temperatures have been analyzed. The effects of many key parameters, including the water vapor concentration in the cathode gas channel, the initial membrane water content, the operating current density, and the startup cell temperature, on PEM fuel cell cold-start behaviors have been carefully examined to elucidate the fundamental physics of PEM fuel cell cold starts. Copyright © 2010 John Wiley & Sons, Ltd.

37 citations


Cited by
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TL;DR: In this paper, the authors present the results of a study at the Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and the United Technologies Research Center, East Hartford, Connecticut 06118, USA.
Abstract: aLawrence Berkeley National Laboratory, Berkeley, California 94720, USA bLos Alamos National Laboratory, Los Alamos, New Mexico 87545, USA cUnited Technologies Research Center, East Hartford, Connecticut 06118, USA dSchool of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom eChemical and Biomolecular Engineering Department, University of California, Berkeley, California 94720, USA fFuel Cell Research and Development, General Motors, Pontiac, Michigan 48340, USA gBallard Power Systems, Burnaby, British Columbia V5J 5J8, Canada hFuel Cell Research Centre, Queens University, Kingston, Ontario K7L 3N6, Canada iDepartment of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA jDepartment of Mechanical Aerospace and Biomedical Engineering, University of Tennessee at Knoxville, Knoxville, Tennessee 37996, USA kDepartment of Mechanical Engineering Technology, SUNY Alfred State College, Alfred, New York 14802, USA lDepartment of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G, Canada

428 citations

Journal ArticleDOI
01 Aug 2020
TL;DR: In this article, the authors present the most recent status of polymer electrolyte membrane (PEM) fuel cell applications in the portable, stationary, and transportation sectors and describe the important fundamentals for the further advancement of fuel cell technology in terms of design and control optimization, cost reduction, and durability improvement.
Abstract: Polymer electrolyte membrane (PEM) fuel cells are electrochemical devices that directly convert the chemical energy stored in fuel into electrical energy with a practical conversion efficiency as high as 65%. In the past years, significant progress has been made in PEM fuel cell commercialization. By 2019, there were over 19,000 fuel cell electric vehicles (FCEV) and 340 hydrogen refueling stations (HRF) in the U.S. (~8,000 and 44, respectively), Japan (~3,600 and 112, respectively), South Korea (~5,000 and 34, respectively), Europe (~2,500 and 140, respectively), and China (~110 and 12, respectively). Japan, South Korea, and China plan to build approximately 3,000 HRF stations by 2030. In 2019, Hyundai Nexo and Toyota Mirai accounted for approximately 63% and 32% of the total sales, with a driving range of 380 and 312 miles and a mile per gallon (MPGe) of 65 and 67, respectively. Fundamentals of PEM fuel cells play a crucial role in the technological advancement to improve fuel cell performance/durability and reduce cost. Several key aspects for fuel cell design, operational control, and material development, such as durability, electrocatalyst materials, water and thermal management, dynamic operation, and cold start, are briefly explained in this work. Machine learning and artificial intelligence (AI) have received increasing attention in material/energy development. This review also discusses their applications and potential in the development of fundamental knowledge and correlations, material selection and improvement, cell design and optimization, system control, power management, and monitoring of operation health for PEM fuel cells, along with main physics in PEM fuel cells for physics-informed machine learning. The objective of this review is three fold: (1) to present the most recent status of PEM fuel cell applications in the portable, stationary, and transportation sectors; (2) to describe the important fundamentals for the further advancement of fuel cell technology in terms of design and control optimization, cost reduction, and durability improvement; and (3) to explain machine learning, physics-informed deep learning, and AI methods and describe their significant potentials in PEM fuel cell research and development (R&D).

208 citations

Journal ArticleDOI
TL;DR: In this article, a review of recent progress in thermal management for PEM fuel cells is summarized with in-depth discussion on the waste heat generation mechanisms, thermal analysis, non-isothermal two-phase flow, cooling methods, cold starts, and relevant material properties and durability.

91 citations

Journal ArticleDOI
TL;DR: In this paper, a generic framework for describing the two-dimensional spatiotemporal evolution of gaseous, liquid and solid phases, as well as their interdependence with interfacial (electro-)chemistry and microstructure in a continuum description is presented.
Abstract: Multi-phase management is crucial for performance and durability of electrochemical cells such as batteries and fuel cells. In this paper we present a generic framework for describing the two-dimensional spatiotemporal evolution of gaseous, liquid and solid phases, as well as their interdependence with interfacial (electro-)chemistry and microstructure in a continuum description. The modeling domain consists of up to seven layers (current collectors, channels, electrodes, separator/membrane), each of which can consist of an arbitrary number of bulk phases (gas, liquid, solid) and connecting interfaces (two-phase or multi-phase boundaries). Bulk and interfacial chemistry is described using global or elementary kinetic reactions. Multi-phase management is coupled to chemistry and to mass and charge transport within bulk phases. The functionality and flexibility of this framework is demonstrated using four application areas in the context of post-lithium-ion batteries and fuel cells, that is, lithium-sulfur (Li-S) cells, lithiumoxygen (Li-O) cells, solid oxide fuel cells (SOFC) and polymer electrolyte membrane fuel cells (PEFC). The results are compared to models available in literature and properties of the generic framework are discussed.

89 citations

Journal ArticleDOI
TL;DR: A comprehensive review dedicated to engineers of the recent research progress on the PEMFC cold start problems is presented and a detailed review of cold startup strategies based on an exhaustive survey of journal papers and patents is concluded.
Abstract: Proton exchange membrane fuel cell (PEMFC) can be a significant eco-friendly alternative power source for vehicles. However, under subfreezing conditions, cell degradation and irreversible performance decay can occur because of ice formation and repetitive thaw/freeze cycles. These problems have limited the further commercialization of PEMFC in cold weather countries. Thus, many improvements have been made to repair the freeze protection and rapid cold startup problems in PEMFC vehicles. In this paper, a comprehensive review dedicated to engineers of the recent research progress on the PEMFC cold start problems is presented. Systems and methods for fuel cell shutdown are summarized and classified into two categories: purge solution and material to avoid freezing. Regarding the system and solutions for PEMFC cold startup, different heating solutions are classified into two main groups depending on their heating sources and categorized as internal and external heating methods. This paper concludes with a detailed review of cold startup strategies based on an exhaustive survey of journal papers and patents.

88 citations