In-game adaptation of a navigation mesh cell path

Differences in the Heat Transfer at the Core-Reflector Boundary of the PBMR Due to the Use of Different Numerical Methods

Volume 3: Thermal Hydraulics; Current Advanced Reactors: Plant Design, Construction, Workforce and Public Acceptance ◽

10.1115/icone17-75156 ◽

2009 ◽

Author(s):

Pieter S. du Toit ◽

Onno Ubbink

Keyword(s):

Two Dimensions ◽

Heat Sources ◽

Coarse Mesh ◽

One Dimensional ◽

Root Cause ◽

The Core ◽

Modified Method ◽

The Difference ◽

Horizontal Slice ◽

Mesh Cell

The PBMR (Pebble Bed Modular Reactor) is a High-Temperature Gas-cooled Reactor (HTGR) concept. One of the exercises of the PBMR benchmark of the Organization for Economic Cooperation and Development (OECD) is a steady state two-dimensional (2D) thermal-hydraulics simulation of a simplified PBMR with prescribed heat sources. Two different programs were used to model this exercise. They predicted similar core temperatures but the side reflector temperatures next to the core differed by more than 30 °C (when using a relatively coarse mesh). The underlying methods define temperatures at either vertices (VC) or at mesh cell centres (CC). A study was undertaken using one-dimensional (1D) implementations of the VC and CC methods to model a horizontal slice through the core. This study revealed the root cause of the different predictions. A modified version of the 1D CC method was developed that essentially predicts the same temperatures as the VC method. The extension of the modified method to two dimensions is under investigation. If the difference in predicted temperatures next to the core can be eliminated or reduced, then the focus can shift to other differences between the results of the two programs.

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A Multimoment Constrained Finite-Volume Model for Nonhydrostatic Atmospheric Dynamics

Monthly Weather Review ◽

10.1175/mwr-d-12-00144.1 ◽

2013 ◽

Vol 141 (4) ◽

pp. 1216-1240 ◽

Cited By ~ 20

Author(s):

Xingliang Li ◽

Chungang Chen ◽

Xueshun Shen ◽

Feng Xiao

Keyword(s):

Finite Volume ◽

Evolution Equations ◽

Complex Geometry ◽

High Order ◽

Computationally Efficient ◽

Dynamical Core ◽

Benchmark Tests ◽

Volume Method ◽

Further Development ◽

Mesh Cell

Abstract The two-dimensional nonhydrostatic compressible dynamical core for the atmosphere has been developed by using a new nodal-type high-order conservative method, the so-called multimoment constrained finite-volume (MCV) method. Different from the conventional finite-volume method, the predicted variables (unknowns) in an MCV scheme are the values at the solution points distributed within each mesh cell. The time evolution equations to update the unknown point values are derived from a set of constraint conditions based on the multimoment concept, where the constraint on the volume-integrated average (VIA) for each mesh cell is cast into a flux form and thus guarantees rigorously the numerical conservation. Two important features make the MCV method particularly attractive as an accurate and practical numerical framework for atmospheric and oceanic modeling. 1) The predicted variables are the nodal values at the solution points that can be flexibly located within a mesh cell (equidistant solution points are used in the present model). It is computationally efficient and provides great convenience in dealing with complex geometry and source terms. 2) High-order and physically consistent formulations can be built by choosing proper constraints in view of not only numerical accuracy and efficiency but also underlying physics. In this paper the authors present a dynamical core that uses the third- and the fourth-order MCV schemes. They have verified the numerical outputs of both schemes by widely used standard benchmark tests and obtained competitive results. The present numerical core provides a promising and practical framework for further development of nonhydrostatic compressible atmospheric models.

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Qualitative analysis of edible oil oxidation by FTIR spectroscopy using a mesh “cell”

Analytical Methods ◽

10.1039/c5ay00438a ◽

2015 ◽

Vol 7 (10) ◽

pp. 4328-4333 ◽

Cited By ~ 11

Author(s):

Lirong Xu ◽

Tao Fei ◽

Qinghua Li ◽

Xiuzhu Yu ◽

Lei Liu

Keyword(s):

Qualitative Analysis ◽

Ftir Spectroscopy ◽

Detection Method ◽

Edible Oil ◽

Oil Oxidation ◽

Qualitative Detection ◽

Mesh Cell

To develop a feasible, green, and fast qualitative detection method for identifying edible oil oxidation, the qualitative discrimination between oxidised and non-oxidised oils was calibrated based on FTIR procedures, which used a mesh cell as a spectral acquisition accessory in combination with Mahalanobis analysis.

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A rapid method for evaluating the edible oil oxidative stability during ambient storage by FTIR spectroscopy using a mesh cell

Analytical Methods ◽

10.1039/c6ay01511e ◽

2016 ◽

Vol 8 (25) ◽

pp. 5117-5122 ◽

Cited By ~ 5

Author(s):

Lirong Xu ◽

Xiuzhu Yu ◽

Lei Liu ◽

Mengjun Li ◽

Rui Zhang

Keyword(s):

Oxidative Stability ◽

Ftir Spectroscopy ◽

Rapid Method ◽

Functional Group ◽

Edible Oils ◽

Edible Oil ◽

Ambient Storage ◽

Mesh Cell

Changes of functional group spectra of edible oils during oxidation on a mesh cell.

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An unstructured mesh cell-centered control volume method for simulating heat and mass transfer in porous media: Application to softwood drying—Part II: The anisotropic model

Applied Mathematical Modelling ◽

10.1016/0307-904x(95)00082-u ◽

1995 ◽

Vol 19 (11) ◽

pp. 668-674 ◽

Cited By ~ 10

Author(s):

I.W. Turner ◽

W.J. Ferguson

Keyword(s):

Mass Transfer ◽

Porous Media ◽

Heat And Mass Transfer ◽

Unstructured Mesh ◽

Control Volume ◽

Control Volume Method ◽

Anisotropic Model ◽

Volume Method ◽

Mesh Cell

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Tracking Sensory Characteristics of Virgin Olive Oils During Storage: Interpretation of Their Changes from a Multiparametric Perspective

Molecules ◽

10.3390/molecules25071686 ◽

2020 ◽

Vol 25 (7) ◽

pp. 1686 ◽

Cited By ~ 3

Author(s):

Ana Lobo-Prieto ◽

Noelia Tena ◽

Ramón Aparicio-Ruiz ◽

María T. Morales ◽

Diego L. García-González

Keyword(s):

Oxidation Process ◽

Virgin Olive Oil ◽

Stability Index ◽

Quality Parameters ◽

Sensory Characteristics ◽

Virgin Olive Oils ◽

Pet Bottles ◽

Olive Oils ◽

Off Flavors ◽

Mesh Cell

Virgin olive oil is inevitably subject to an oxidation process during storage that can affect its stability and quality due to off-flavors that develop before the oil surpasses its ‘best before’ date. Many parameters are involved in the oxidation process at moderate conditions. Therefore, a multiparametric study is necessary to establish a link between physico-chemical changes and sensory quality degradation in a real storage experiment. In this context, a storage experiment of 27 months was performed for four monovarietal virgin olive oils, bottled in transparent 500-mL PET bottles and subjected to conditions close to a supermarket scenario. Volatile composition, quality parameters and phenolic compounds were determined monthly. Simultaneously, an accredited sensory panel assessed their sensory characteristics. The stability of the fresh samples was also studied with the oxidative stability index (OSI) and mesh cell-FTIR. (E)-2-hexenal, (Z)-3-hexen-1-ol and (E)-2-hexen-1-ol were identified as markers of the fruity attribute. Hexanal and nonanal were also identified as compounds that were associated with the rise of median of defect during storage. Some disagreements were observed between the sensory assessment and the OSI analyzed by Rancimat. However, the increase of concentration of rancid markers agreed with the increase of aldehyde band measured with mesh cell-FTIR.

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