ONE-DIMENSIONAL HYDRODYNAMIC MODEL SIMULATING WATER STAGE IN OPEN CHANNELS (WS-1)

2010 ◽  
Vol 01 (02) ◽  
pp. 303-316
Author(s):  
M. A. NASSAR
Keyword(s):  
Unsteady Flow ◽  
Hydrodynamic Model ◽  
Water Levels ◽  
Open Channels ◽  
Nile River ◽  
Improvement Project ◽  
One Dimensional ◽  
Water Stage ◽  
The Impact ◽  
Good Agreement

One-dimensional (1D) numerical model was developed to simulate water stage in open channels in order to suggest solutions for practical problems in the Nile River and its branches. The continuity and momentum equations describe the unsteady flow were solved using the finite difference technique. The developed model is verified using two types of data. The first type, simulating steady flow, is a field data collected at Elbogdady reach. It is a reach located 712.80 km upstream of Roda's staff gauge on the Nile River. The second type, simulating unsteady flow, is a result of the 1D SOBEK model. It is simulating the flow field at El-Mahrousa canal. It is one of El-Kanobia canal branches at 11.47 km left side, which is fed from El-Mahmoudia canal. Simplifications were made to simulate the flow patterns around the hydraulic structures using the developed hydrodynamic model. Actually, the water levels in many branch canals under continuous flow after implementation of Irrigation Improvement Project (IIP) need to be checked. The model could be applied to estimate the water stage under different abstraction values where some reaches of the Nile River and its branch suffering. In addition, it can be used to assess the impact of water allocation. Good agreement was observed between the model results and the field observations.

scholarly journals Study of Unsteady Flow in a Heat Exchanger by the Method of Characteristics

1992 ◽  
Vol 114 (4) ◽  
pp. 459-463 ◽  
Author(s):  
Yuan Mao Huang
Keyword(s):  
Heat Exchanger ◽  
Unsteady Flow ◽  
Transfer Rate ◽  
Method Of Characteristics ◽  
Governing Equations ◽  
One Dimensional ◽  
The Method Of Characteristics ◽  
Improvement Factor ◽  
The One ◽  
Good Agreement

The one-dimensional, unsteady flow in an air-to-air heat exchanger is studied. The governing equations are derived and the method of characteristics with the uniform interval scheme is used in the analysis. The effect of the fin improvement factor on the air temperature in the heat exchanger and the heat transfer rate of the heat exchanger, and air properties in the heat exchanger are analyzed. The numerical results are compared and show good agreement with the available data.

Hydraulic and Hydrologic Analysis of Unsteady Flow in Prismatic Open Channel

2018 ◽  
Author(s):  
Eugene Retsinis ◽  
Erna Daskalaki ◽  
Panos Papanicolaou
Keyword(s):  
Unsteady Flow ◽  
Open Channels ◽  
Finite Difference Schemes ◽  
Flow Conditions ◽  
Commercial Software ◽  
One Dimensional ◽  
Hydrologic Analysis ◽  
Dependent Variables ◽  
Implicit Finite Difference ◽  
Implicit Code

Comparison between hydraulic and hydrologic computational methods is conducted in this study, regarding prismatic open channels under unsteady subcritical flow conditions. One-dimensional unsteady flow continuity and momentum equations are solved using explicit and implicit finite difference schemes for a symmetrical trapezoidal cross section, where the flow discharge and depth are the dependent variables. The results have been compared to those derived from Muskingum-Cunge hydraulic/hydrologic method as well as the commercial software HEC-RAS. The results from explicit and implicit code compare well to those from commercial software and hydraulic/hydrologic methods for long prismatic channels, thus directing the hydraulic engineer to quick preliminary design of prismatic open channels for unsteady flow with satisfactory accuracy.

Unsteady One-Dimensional Compressible Frictional Flow with Heat Transfer

1972 ◽  
Vol 14 (6) ◽  
pp. 365-369 ◽  
Author(s):  
R. I. Issa ◽  
D. B. Spalding
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Unsteady Flow ◽  
Hybrid Method ◽  
Numerical Procedure ◽  
Rectangular Grid ◽  
Paper Briefly ◽  
One Dimensional ◽  
Flow Problems ◽  
Good Agreement

The paper briefly describes a numerical procedure for solving problems of one-dimensional, unsteady, compressible, frictional flows with heat transfer. The procedure is based on the Hartree ‘hybrid’ method which combines the use of a rectangular grid with the use of characteristics. The main features of the procedure are its applicability and ease of adaptability to complex unsteady-flow problems. Another feature is the simplicity of its programming for a computer. Computations for flows in shock tubes are presented; they are in good agreement with previously published experimental data.

scholarly journals Modelling Investigation of the Thermal Treatment of Ash-Contaminated Particulate Filters

2021 ◽  
Author(s):  
Chung Ting Lao ◽  
Jethro Akroyd ◽  
Alastair Smith ◽  
Neal Morgan ◽  
Kok Foong Lee ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Thermal Treatment ◽  
Crack Formation ◽  
Management Strategies ◽  
Dimensional Model ◽  
One Dimensional ◽  
Particulate Filters ◽  
Ash Layer ◽  
The Impact ◽  
Good Agreement

AbstractThis paper investigates the impact of thermal treatment on the pressure drop of particulate filters containing ash deposits. A one-dimensional model has been developed and applied to describe the deposition of soot and ash particles, and estimate the spatial distribution of the deposits in such filters. Phenomenological models have been developed to describe the potential sintering and cracking of the ash deposits caused by thermal treatment of the filter. The model results are in good agreement with experimental measurements of the reduction in the pressure drop in thermally treated filters. It was found that crack formation in the ash layer can lead to significant reduction of the pressure drop at relatively low temperatures. Sintering of ash deposits in the wall and the ash plug also contributes towards a decrease in filter pressure drop at higher temperatures. This work is the first attempt to model the impact of the thermal treatment of ash in particulate filters in order to support the development of future ash management strategies. The cracking of the ash layer during the thermal treatment has been identified to be the most critical effect for pressure drop reduction.

APPLICATION OF ELASTIC MATERIALS IN PROTECTION FROM STRONG IMPACTS

2004 ◽  
Vol 18 (14) ◽  
pp. 1977-1990
Author(s):  
MASKOVIC D. LJILJANA ◽  
MOHORA EMILIJAN ◽  
TOSIC S. BRATISLAV ◽  
VUJOVIC R. RATKO
Keyword(s):  
Elastic Material ◽  
Short Pulse ◽  
Three Dimensional ◽  
Polymer Materials ◽  
Elastic Materials ◽  
One Dimensional ◽  
Spherical Surfaces ◽  
The Impact ◽  
Theoretical Results ◽  
Good Agreement

The analysis of the behavior of elastic material subject to strong short pulse impact has shown that only one-dimensional structures support the impact without destruction. Compact two- and three-dimensional structures are destroyed during the impact along circular lines and spherical surfaces. For that reason, web-like shields are proposed for the protection of man and equipment. Polymer materials are most suitable for the production of web-like shields since they are made of fibers and highly stress resistant. Theoretical results are experimentally tested and the good agreement with theory was found.

scholarly journals Hydraulic and Hydrologic Analysis of Unsteady Flow in Prismatic Open Channel

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 571 ◽  
Author(s):  
Eugene Retsinis ◽  
Erna Daskalaki ◽  
Panos Papanicolaou
Keyword(s):  
Unsteady Flow ◽  
Open Channels ◽  
Finite Difference Schemes ◽  
Flow Conditions ◽  
Commercial Software ◽  
One Dimensional ◽  
Hydrologic Analysis ◽  
Dependent Variables ◽  
Implicit Finite Difference ◽  
Implicit Code

Comparison between hydraulic and hydrologic computational methods is conducted in this study, regarding prismatic open channels under unsteady subcritical flow conditions. One-dimensional unsteady flow continuity and momentum equations are solved using explicit and implicit finite difference schemes for a symmetrical trapezoidal cross section, where the flow discharge and depth are the dependent variables. The results have been compared to those derived from Muskingum-Cunge hydraulic/hydrologic method as well as the commercial software HEC-RAS. The results from explicit and implicit code compare well to those from commercial software and hydraulic/hydrologic methods for long prismatic channels, thus directing the hydraulic engineer to quick preliminary design of prismatic open channels for unsteady flow with satisfactory accuracy.

Longitudinal Dispersion in a Stream Calculated by One Dimensional Numerical Model

1983 ◽  
Vol 14 (1) ◽  
pp. 41-46
Author(s):  
Torulv Tjomsland
Keyword(s):  
Numerical Model ◽  
Field Measurements ◽  
Longitudinal Dispersion ◽  
One Dimensional ◽  
Water Stage ◽  
Good Agreement

A one-dimensional numerical model was used to simulate water stage and dispersion of matter in a stream. The calculated results show quite good agreement with field measurements.

scholarly journals The influence of weight coefficients in the Preissman scheme on flows in the lower Odra river network using the Hec-Ras software

2018 ◽  
Vol 23 ◽  
pp. 00024
Author(s):  
Robert Mańko
Keyword(s):  
River Network ◽  
Main Flow ◽  
Open Channels ◽  
Channel Axis ◽  
One Dimensional ◽  
Water Flows ◽  
Odra River ◽  
Saint Venant Equations ◽  
The Impact ◽  
Weight Coefficients

Mathematical modelling of water flows processes in rivers and open channels for many years has been target of researches for hydrotechnics and hydrologists. For flows forecasting in open channels models based on one-dimensional equations are mostly used. This models are assuming that the main flow component is parallel to the channel axis is substantially larger than others, so it can ignore them. One of the most effective methods for solving de Saint-Venant equations is the finite difference method with using four-point Preissman Scheme. In this paper an analysis of the impact of Preissman weighting parameters on flows in the lower Odra river network.

Modeling of Tread Block Contact Mechanics Using Linear Viscoelastic Theory3

2008 ◽  
Vol 36 (3) ◽  
pp. 211-226 ◽  
Author(s):  
F. Liu ◽  
M. P. F. Sutcliffe ◽  
W. R. Graham
Keyword(s):  
High Speed ◽  
Slip Rate ◽  
Material Model ◽  
Contact Forces ◽  
Block Modeling ◽  
Rate Dependent ◽  
Linear Viscoelastic Material ◽  
Linear Viscoelastic ◽  
The Impact ◽  
Good Agreement

Abstract In an effort to understand the dynamic hub forces on road vehicles, an advanced free-rolling tire-model is being developed in which the tread blocks and tire belt are modeled separately. This paper presents the interim results for the tread block modeling. The finite element code ABAQUS/Explicit is used to predict the contact forces on the tread blocks based on a linear viscoelastic material model. Special attention is paid to investigating the forces on the tread blocks during the impact and release motions. A pressure and slip-rate-dependent frictional law is applied in the analysis. A simplified numerical model is also proposed where the tread blocks are discretized into linear viscoelastic spring elements. The results from both models are validated via experiments in a high-speed rolling test rig and found to be in good agreement.

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