The Experts below are selected from a list of 17376 Experts worldwide ranked by ideXlab platform

Xiang Yin - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on optimal Shell-to-tube Radius ratio of a vertical Shell-and-tube latent heat energy storage system
    Solar Energy, 2020
    Co-Authors: Gang Shen, Xiaolin Wang, Andrew Chan, Feng Cao, Xiang Yin
    Abstract:

    Abstract This study aims to investigate the optimal Shell-to-tube Radius ratio in a vertical Shell-and-tube latent heat thermal energy storage system with phase change material packed in the annulus and heat transfer fluid circulating in the central tube. A conjugate thermodynamic model is developed and validated, and then applied to investigate two series of system configurations: varying the phase change material Shell Radius at a fixed heat transfer fluid tube Radius and varying the heat transfer fluid tube Radius at a fixed Shell Radius. The numerical investigation compares and evaluates energy storage/retrieval density, energy storage/retrieval rate, and total stored/retrieved energy capacity under different Shell-to-tube Radius ratios. The results show that the thermal behaviour in both series of units is very similar. The optimal Radius ratio slightly increases as the total charging/discharging time increases. The unit height has a gentle effect on the optimal Radius ratio in the charging process and a negligible influence in the discharging process. By balancing the energy storage/retrieval density, energy storage/retrieval rate, and storage/retrieval capacity in both charging and discharging processes, the optimal Shell-to-tube Radius ratio is found to be around 5 for both series of configurations at the studied total charging/discharging times.

Marcel Lacroix - One of the best experts on this subject based on the ideXlab platform.

  • numerical simulation of a Shell and tube latent heat thermal energy storage unit
    Solar Energy, 1993
    Co-Authors: Marcel Lacroix
    Abstract:

    Abstract A theoretical model was developed to predict the transient behavior of a Shell-and-tube storage unit with the phase change material (PCM) on the Shell side and the heat transfer fluid (HTF) circulating inside the tubes. The multidimensional phase change problem is tackled with an enthalpy-based method coupled to the convective heat transfer from the HTF. The numerical predictions are validated with experimental data. A series of numerical experiments are then undertaken to assess the effects of various thermal and geometric parameters on the heat transfer process and on the behavior of the system. Results show that the Shell Radius, the mass flow rate, and the inlet temperature of the HTF must be chosen carefully in order to optimize the performance of the unit.

  • study of the heat transfer behavior of a latent heat thermal energy storage unit with a finned tube
    International Journal of Heat and Mass Transfer, 1993
    Co-Authors: Marcel Lacroix
    Abstract:

    Abstract A theoretical model for predicting the transient behavior of a Shell-and-tube storage unit with the PCM on the Shell side and the HTF circulating inside the tubes is presented. The tubes are bare or finned. The multidimensional phase change problem is tackled with an enthalpy based method coupled to the convective heat transfer from the HTF. The numerical model is validated with experimental data. A series of numerical experiments are then undertaken to assess the effects of (1) the Shell Radius, (2) the mass flow rate and inlet temperature of the HTF and (3) the presence of fins attached to the inner tubes on the thermal behavior of the thermal unit. Results show that the annular fins are most effective for moderate mass flow rates and small inlet temperatures.

Liudmila G. Astafyeva - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear absorption, scattering, and extinction of laser radiation by two-layered spherical system-gold nanoparticle and vapor Shell in water
    Laser Physics, 2011
    Co-Authors: Victor K. Pustovalov, Liudmila G. Astafyeva
    Abstract:

    Nonlinear absorption, scattering and extinction of laser radiation with wavelengths 532, 633 nm by spherical gold nanoparticles (NPs) with radii in the range of 5-100 nm placed in water and heated by laser radiation with formation and expansion of vapor nanoShells is theoretically investigated. Decrease of absorp� tion, decrease and subsequent increase of scattering and extinction with increasing of Shell Radius beginning from the initial period of Shell expansion is established. Optical indicatrixes and nonlinear behavior of scat� tered radiation are investigated including the examination of these characteristics during the adiabatic expan� sion of vapor Shell. Formation of vapor nanoShells (bubbles) as a result of the action of short laser pulses on NPs placed in tissue was proposed for cutting of tissue.

  • Nonlinear thermo-optical properties of two-layered spherical system of gold nanoparticle core and water vapor Shell during initial stage of Shell expansion
    Nanoscale research letters, 2011
    Co-Authors: Victor K. Pustovalov, Liudmila G. Astafyeva
    Abstract:

    Nonlinear thermo-optical properties of two-layered spherical system of gold nanoparticle core and water vapor Shell, created under laser heating of nanoparticle in water, were theoretically investigated. Vapor Shell expansion leads to decreasing up to one to two orders of magnitude in comparison with initial values of scattering and extinction of the radiation with wavelengths 532 and 633 nm by system while Shell Radius is increased up to value of about two radii of nanoparticle. Subsequent increasing of Shell Radius more than two radii of nanoparticle leads to rise of scattering and extinction properties of system over initial values. The significant decrease of radiation scattering and extinction by system of nanoparticle-vapor Shell can be used for experimental detection of the energy threshold of vapor Shell formation and investigation of the first stages of its expansion.

Li Jun - One of the best experts on this subject based on the ideXlab platform.

  • The transient responses of two-layered cylindrical Shells attacked by underwater explosive shock waves
    Composite Structures, 2010
    Co-Authors: Hu Gangyi, Xia Fei, Li Jun
    Abstract:

    Abstract An approximation solution is introduced for the dynamic response of a two-layered cylindrical Shell of circular cross-section subjected to an underwater explosive shock wave. The solution is obtained within the framework of the Flugge thin Shell theory and the reflected-afterflow-virtual-source (RAVS) method is used to account for the fluid–structure interaction. Detailed numerical computations are carried out, in dimensionless form, for the cases of infinitely long two-layered cylindrical Shells. Time histories of nondimensional radial velocity, mid-surface strain, 0th mode radial displacement and 1st mode radial velocity are presented in graphical form and the effects of elastic modulus, Shell Radius and thickness on the transient response characteristics of the Shells are investigated.

  • Transient Response of an Orthotropic Cylindrical Shell to an Underwater Explosive Loading
    Journal of Reinforced Plastics and Composites, 2008
    Co-Authors: Li Jun, Hua Hong-xing
    Abstract:

    The transient response of an elastic orthotropic cylindrical Shell immersed in an acoustic fluid and subjected to a shock loading is investigated in this article. The Sanders thin Shell theory is employed in the analysis and the governing equations of the motion for orthotropic cylindrical Shell are derived by using Hamilton's principle. The type of loading is the exponentially decaying plane acoustic wave induced by underwater explosion. The reflected-afterflow virtual-source (RAVS) technique is used to simulate the fluid-structure interaction. The numerical analyses are performed to look into the influences of the Shell Radius and thickness upon the non-dimensional radial velocity, mid-surface strain, 0th mode radial displacement and 1st mode radial velocity of the Shells.

Hsien Chih Chen - One of the best experts on this subject based on the ideXlab platform.

  • Buckling optimization of laminated truncated conical Shells subjected to external hydrostatic compression
    Composites Part B: Engineering, 2018
    Co-Authors: Hsien Chih Chen
    Abstract:

    Abstract Buckling analyses of laminated truncated conical Shells subjected to external hydrostatic compression are carried out by employing the Abaqus finite element program. The critical buckling loads of these truncated conical Shells with a given material system are maximized with respect to fiber orientations by using the golden section method. Through parametric studies, the influences of the end condition, Shell thickness, Shell length, Shell Radius ratio and cutout size on the optimal buckling loads, the associated optimal fiber orientations and the associated buckling modes are demonstrated and discussed.