The Water Transferred of Meandering River in Cellular Model

2012 ◽  
Vol 452-453 ◽  
pp. 842-845
Author(s):  
Min Zhang ◽  
Rui Xun Lai
Keyword(s):  
Flow Direction ◽  
Field Measurements ◽  
Treatment Method ◽  
Special Treatment ◽  
Cellular Model ◽  
Channel Processes ◽  
Flow Routing ◽  
The Real ◽  
Meandering River ◽  
Routing Scheme

We have known that many of the main features of river can be captured in a relatively simple cellular computer model. Here we examine some of the detailed characteristics of this model. We show a new tangential angle and special treatment method in curvature channel in a simple cellular model. The water distribute will be determined by the tangential angle which represent the flow direction. And the same tangential angle cellular in curvature reach will be transport in one group in filially. The results show it can make the flow routing conformed to the real river, and solve the question of curve bending coefficient is too large. The results of the routing scheme are compared with field measurements of cross-section, with the predictions of a more close to the real. It’s indicate that the curvature flow routing scheme outlined here is able to overcome some of the limitations of previous simple cellular automata models and may be suitable for use in curvature reach of river modeling water and sediment transport and channel change in complex fluvial environments. As such this research represents a small and ongoing contribution to the field of numerical simulation of curvature channel processes.

scholarly journals A reduced-complexity model for river delta formation – Part 2: Validation of the flow routing scheme

2014 ◽  
Vol 2 (2) ◽  
pp. 871-910
Author(s):  
M. Liang ◽  
N. Geleynse ◽  
D. A. Edmonds ◽  
P. Passalacqua
Keyword(s):  
Flow Field ◽  
River Delta ◽  
Sediment Flux ◽  
Channel Processes ◽  
Channel Network ◽  
Flow Routing ◽  
Routing Scheme ◽  
Delta Formation ◽  
Flow Through ◽  
Reduced Complexity

Abstract. In a companion paper (Liang et al., 2014) we introduced a Reduced-Complexity Model (RCM) for river delta formation, developed using a parcel-based "weighted random walk" method for routing water and sediment flux. This model (referred to as "DeltaRCM") consists of a flow routing scheme as the hydrodynamic component (referred to as "FlowRCM") and a set of sediment transport rules as the morphodynamic component. In this work, we validate the flow routing scheme (FlowRCM) via a series of hydrodynamic tests by comparing the model outputs to Delft3D and theoretical predictions. These tests are designed to reveal the capability of FlowRCM to resolve flow field features that are critical to delta dynamics at the level of channel processes. In particular, we focus on (1) backwater profile, (2) flow around a mouth bar, (3) flow through a single bifurcation, and (4) flow through a distributary channel network. We show that while the simple rules are not able to reproduce all fine-scale flow structures, FlowRCM does capture flow field features that are essential to deltaic processes such as bifurcations and avulsions. Finally, we discuss advantages and limitations of FlowRCM and identify environments most suitable for it.

Implementation Issues in 3D Wind Flow Predictions Over Complex Terrain

2006 ◽  
Vol 128 (4) ◽  
pp. 539-553 ◽  
Author(s):  
John Prospathopoulos ◽  
Spyros G. Voutsinas
Keyword(s):  
Wind Energy ◽  
Boundary Conditions ◽  
Complex Terrain ◽  
Flow Direction ◽  
Region Of Interest ◽  
Field Measurements ◽  
Navier Stokes ◽  
Wind Flow ◽  
Computational Domain

Practical aspects concerning the use of 3D Navier-Stokes solvers as prediction tools for micro-siting of wind energy installations are considered. Micro-siting is an important issue for a successful application of wind energy in sites of complex terrain. There is a constantly increasing interest in using mean wind flow predictions based on Reynolds averaged Navier-Stokes (RANS) solvers in order to minimize the number of required field measurements. In this connection, certain numerical aspects, such as the extent of the numerical flow domain, the choice of the appropriate inflow boundary conditions, and the grid resolution, can decisively affect the quality of the predictions. In the present paper, these aspects are analyzed with reference to the Askervein hill data base of full scale measurements. The objective of the work is to provide guidelines with respect to the definition of appropriate boundary conditions and the construction of an adequate and effective computational grid when a RANS solver is implemented. In particular, it is concluded that (a) the ground roughness affects the predictions significantly, (b) the computational domain should have an extent permitting the full development of the flow before entering the region of interest, and (c) the quality of the predictions at the local altitude maxima depends on the grid density in the main flow direction.

scholarly journals A new parameterization scheme of the real part of the ambient aerosols refractive index

2019 ◽  
Author(s):  
Gang Zhao ◽  
Tianyi Tan ◽  
Weilun Zhao ◽  
Song Guo ◽  
Ping Tian ◽  
...  
Keyword(s):  
Refractive Index ◽  
Radiative Forcing ◽  
Field Measurements ◽  
Effective Density ◽  
Parameterization Scheme ◽  
Chemical Components ◽  
Ambient Aerosols ◽  
Ambient Aerosol ◽  
The Real ◽  
Aerosol Radiative

Abstract. The refractive index of ambient aerosols, which directly determines the aerosol optical properties, is widely used in atmospheric models and remote sensing. Traditionally, the real part of the refractive index (RRI) is mainly parameterized by the measurement of ambient aerosol main inorganic components. In this paper, the characteristics of the ambient aerosol RRI are studied based on the field measurement in the East China. Results show that the ambient aerosol RRI varies significantly between 1.36 and 1.56. The direct aerosol radiative forcing is estimated to vary by 40 % corresponding to the variation of the measured aerosol RRI. We find that the ambient aerosol RRI is highly related with the aerosol effective density (ρeff) rather than the main chemical components. However, parameterization schemes of the ambient aerosol RRI by ρeff are not available due to the lack of corresponding simultaneous field measurements. For the first time, the size-resolved ambient aerosol RRI and ρeff are measured simultaneously by our designed measurement system. A new parameterization scheme of the ambient aerosols RRI using ρeff is proposed. The measured and parameterized RRI agree well with the correlation coefficient of 0.76. Knowledge of the ambient aerosol RRI would improve our understanding of the ambient aerosol radiative effects.

scholarly journals A reduced-complexity model for river delta formation – Part 2: Assessment of the flow routing scheme

2015 ◽  
Vol 3 (1) ◽  
pp. 87-104 ◽  
Author(s):  
M. Liang ◽  
N. Geleynse ◽  
D. A. Edmonds ◽  
P. Passalacqua
Keyword(s):  
Flow Field ◽  
River Delta ◽  
Sediment Flux ◽  
Channel Network ◽  
Flow Routing ◽  
Routing Scheme ◽  
Delta Formation ◽  
Flow Through ◽  
Mouth Bar ◽  
Reduced Complexity

Abstract. In a companion paper (Liang et al., 2015) we introduced a reduced-complexity model (RCM) for river delta formation, developed using a parcel-based "weighted random walk" method for routing water and sediment flux. This model (referred to as DeltaRCM) consists of a flow routing scheme as the hydrodynamic component (referred to as FlowRCM) and a set of sediment transport rules as the morphodynamic component. In this work, we assess the performance of FlowRCM via a series of hydrodynamic tests by comparing the model outputs to Delft3D and theoretical predictions. These tests are designed to reveal the capability of FlowRCM to resolve flow field features that are critical to delta dynamics at the level of channel processes. In particular, we focus on (1) backwater profile, (2) flow around a mouth bar, (3) flow through a single bifurcation, and (4) flow through a distributary channel network. We show that while the simple rules are not able to reproduce all fine-scale flow structures, FlowRCM captures flow field features that are essential to deltaic processes such as bifurcations and avulsions, the partitioning of flux between channels and inundated islands, and the instability of flux distribution at channel mouths which is responsible for mouth-bar growth. Finally, we discuss advantages and limitations of FlowRCM and identify environments most suitable for it.

scholarly journals Assessment of Natural Ventilation System for a Typical Residential House in Poland

2016 ◽  
Vol 22 (3) ◽  
pp. 25-44 ◽  
Author(s):  
Romana Antczak-Jarząbska ◽  
Marek Krzaczek
Keyword(s):  
Natural Ventilation ◽  
Flow Direction ◽  
Air Flow ◽  
Ventilation System ◽  
Winter Season ◽  
Residential Building ◽  
Field Measurements ◽  
Significant Deterioration ◽  
Climate Conditions ◽  
Ventilation Performance

Abstract The paper presents the research results of field measurements campaign of natural ventilation performance and effectiveness in a residential building. The building is located in the microclimate whose parameters differ significantly in relation to a representative weather station. The measurement system recorded climate parameters and the physical variables characterizing the air flow in the rooms within 14 days of the winter season. The measurement results showed that in spite of proper design and construction of the ventilation system, unfavorable microclimatic conditions that differed from the predicted ones caused significant reduction in the efficiency of the ventilation system. Also, during some time periods, external climate conditions caused an opposite air flow direction in the vent inlets and outlets, leading to a significant deterioration of air quality and thermal comfort measured by CO2 concentration and PMV index in a residential area.

scholarly journals Automatic parameterization of a flow routing scheme driven by radar altimetry data: Evaluation in the Amazon basin

2013 ◽  
Vol 49 (1) ◽  
pp. 614-629 ◽  
Author(s):  
Augusto C. V. Getirana ◽  
Aaron Boone ◽  
Dai Yamazaki ◽  
Nelly Mognard
Keyword(s):  
Amazon Basin ◽  
Data Evaluation ◽  
Altimetry Data ◽  
Flow Routing ◽  
Radar Altimetry ◽  
Routing Scheme

A river flow routing scheme for general circulation models

1999 ◽  
Vol 104 (D12) ◽  
pp. 14347-14357 ◽  
Author(s):  
Vivek K. Arora ◽  
Francis H. S. Chiew ◽  
Rodger B. Grayson
Keyword(s):  
General Circulation ◽  
River Flow ◽  
General Circulation Models ◽  
Flow Routing ◽  
Routing Scheme

scholarly journals Solid Waste Incineration Modelling for Advanced Moving Grate Incinerators

2020 ◽  
Vol 12 (19) ◽  
pp. 8007
Author(s):  
Mingtao Jiang ◽  
Adrian C. H. Lai ◽  
Adrian Wing-Keung Law
Keyword(s):  
Solid Waste ◽  
Large Scale ◽  
Real Life ◽  
Field Performance ◽  
Field Measurements ◽  
Waste Incineration ◽  
Waste To Energy ◽  
Pyrolysis Kinetics ◽  
The Real ◽  
Actual Field

Currently, the design of advanced moving grate (AMG) incinerators for solid waste is aided by computational simulations. The simulation approach couples a waste bed model to characterize the incineration processes of the waste material on top of the moving grate, with a computational fluid dynamics (CFD) model to reproduce the heated air movement and reactions in the incinerator space above. However, the simulation results of AMG incinerators are rarely compared with actual field measurements for validation in the literature so far. In this study, we first examine the sensitivity of pyrolysis kinetics in the waste bed model using three existing alternatives. The predictions of combustion characteristics, including the bed height, flow and temperature distributions, composition of stack gases and gas emissions are obtained for the three alternatives and compared with measurements from a simple laboratory furnace. The results show that the pyrolysis kinetics mechanism can significantly affect the outputs from the waste bed model for incineration modelling. Subsequently, we propose a new coupling approach based on a recent AMG waste bed model (which includes the complex pyrolysis kinetics inside the waste bed on top of the moving grate) and the freeboard CFD simulations. The new approach is then used to predict the field performance of a large scale waste-to-energy (WTE) plant and the predictions are compared directly with the real measurements in various operational scenarios. The comparison shows an overall satisfactory agreement in terms of temperature and exit gases composition given the complexity of the real life operations, although the CO emission is slightly underpredicted.

scholarly journals XXIV. Researches in spectrum-analysis in connexion with the spectrum of the sun.—No. IV

1874 ◽  
Vol 164 ◽  
pp. 805-813 ◽  
Keyword(s):  
Royal Society ◽  
Wave Length ◽  
Treatment Method ◽  
Special Treatment ◽  
Metallic Elements ◽  
Chemical Methods ◽  
The Third ◽  
Metallic Salts ◽  
Long Time ◽  
Time Required

I beg to lay before the Royal Society a Map of that portion of the spectra of calcium, strontium, and barium comprised between wave-length 3900 and 4500. This Map has been constructed from photographs of the spectra taken by the method described by me in a former communication (the third paper of this series) to the Society, and I am induced to send it in as a specimen of the results to be obtained by the method in the hope that other observers will co-operate; for I am of opinion that it will be necessary to construct similar maps for all the metallic elements before either our knowledge of the composition of the sun’s reversing layer can be said to be in any way perfect, or we can be said to have a ready means of determining cyclical changes in its composition. The great labour attending and long time required for the construction of these maps results from the universal presence of impurities, even in the purest specimens of the metals or metallic salts prepared by the ordinary chemical methods; and although the method employed is the only one which enables us to eliminate them eventually, this elimination necessitates a photographic comparison of the spectrum mapped with those of all the substances present as impurities. Hence there are numerous records to be discussed, and the discussion requires special treatment. Method of Mapping. The method of treatment which I have employed in constructing the Maps is as follows:— 1. Elimination o f lines due to impurities .—The spectrum of the element is first confronted with the spectra of the substances most likely to be present as impurities, and with those of metals which, according to Thalénn’s measurements, contain in their spectra coincident lines. Lines due to impurities, if any are thus traced, are marked for omission from the Map and their true sources recorded, while any line that is observed to vary in length and thickness in the various photographs is at once suspected to be an impurity line, and if traced to such is likewise marked for omission.

scholarly journals Westward moving dynamic substorm features observed with the IMAGE magnetometer network and other ground-based instruments

1998 ◽  
Vol 16 (4) ◽  
pp. 425-440 ◽  
Author(s):  
H. Lühr ◽  
A. Aylward ◽  
S. C. Bucher ◽  
A. Pajunpää ◽  
K. Pajunpää ◽  
...  
Keyword(s):  
Electric Fields ◽  
Plasma Flow ◽  
Flow Direction ◽  
Field Measurements ◽  
Equivalent Current ◽  
Late Evening ◽  
Reliable Interpretation ◽  
Electric Fields And Currents ◽  
Current Filaments ◽  
The Magnetic Field

Abstract. We present the ground signatures of dynamic substorm features with particular emphasis on the event interpretation capabilities provided by the IMAGE magnetometer network. This array covers the high latitudes from the sub-auroral to the cusp/cleft region. An isolated substorm on 11 Oct. 1993 during the late evening hours exhibited many of well-known features such as the Harang discontinuity, westward travelling surge and poleward leap, but also discrete auroral forms, known as auroral streamers, appeared propagating westward along the centre of the electrojet. Besides the magnetic field measurements, there were auroral observations and plasma flow and conductivity measurements obtained by EISCAT. The data of all three sets of instruments are consistent with the notion of upward field-aligned currents associated with the moving auroral patches. A detailed analysis of the electrodynamic parameters in the ionosphere, however, reveals that they do not agree with the expectations resulting from commonly used simplifying approximations. For example, the westward moving auroral streamers which are associated with field-aligned current filaments, are not collocated with the centres of equivalent current vortices. Furthermore, there is a clear discrepancy between the measured plasma flow direction and the obtained equivalent current direction. All this suggests that steep conductivity gradients are associated with the transient auroral forms. Also self-induction effects in the ionosphere may play a role for the orientation of the plasma flows. This study stresses the importance of multi-instrument observation for a reliable interpretation of dynamic auroral processes.Keywords. Ionosphere (Auroral ionosphere; Electric fields and currents; Ionosphere-magnetosphere interactions).

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