scholarly journals THE MATHEMATICAL MODELLING METHODS APPLYING TO ESTIMATE THE PIPELINES TECHNICAL STATE AND ENVIRONMENT SITUATION

2019 ◽  
pp. 97-103
Author(s):  
A. P. Oliinyk ◽  
G. V. Grigorchuk ◽  
R. M. Govdyak
Keyword(s):  
Boundary Conditions ◽  
Oil And Gas ◽  
Equation System ◽  
Technical Condition ◽  
Original Method ◽  
Two Dimensional ◽  
Navier Stokes Equation ◽  
Emergency Situations ◽  
Negative Impacts ◽  
The Impact

In the context of providing trouble-free operation of oil and gas pipelines and preventing possible negative impacts on the environment, the issues of constructing an integrated mathematical model for assessing the technical condition of pipelines and the impact of emergency situations on the state of the environment in the course of hydrocarbon leakage are considered. The model of the evaluation of the stress-strain state of the pipeline according to the data on the displacement of surface points for the above ground and underground sections is given by constructing the law of motion of the site by known displacements of a certain set of surface points using assumptions about the type of deformation of the sections and reproduction of the deformations and stresses tensors components   on the basis of different models of deformed solid body. The specified model does not require information on the whole complex of forces and loads acting on the investigated object during operation. The flow model has been refined in a pipeline with a violation of its tightness by recording a special type of boundary conditions for a Navier-Stokes equation system in a two-dimensional formulation and developing an original method for its solution on the basis of the finite difference method. In the article the stability conditions of the proposed numerical schemes on basis of the spectral sign of stability are presented. In order to assess possible negative impacts on the environment, a model of propagation of matter at its leakage from the pipeline was developed by solving two-dimensional diffusion equations taking into account the variables and different types of boundary conditions that take into account the number of sources of pollution and their intensity. The results of computations based on computational algorithms implemented by these models and graphic material illustrating these calculations are presented, peculiarities of distribution of harmful substances in the environment near the pipeline are analyzed. Directions of further researches for successful practical realization of the offered models are established.

Gas Turbine Temperature Prediction Using Unsteady CFD and Realistic Non-Uniform 2D Combustor Exit Properties

2008 ◽  
Author(s):  
Fre´de´ric N. Felten ◽  
Semir Kapetanovic ◽  
D. Graham Holmes ◽  
Michael Ostrowski
Keyword(s):  
Boundary Conditions ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Computational Cost ◽  
Computational Domain ◽  
Two Dimensional ◽  
Gas Temperature ◽  
Sliding Mesh ◽  
Flow Gradients ◽  
The Impact

Typical Computational Fluid Dynamics (CFD) studies performed on High Pressure Turbines (HPT) do not include the combustor domain in their analyses. Boundary conditions from the combustor exit have to be prescribed at the inlet of the computational domain for the first HPT nozzle. It is desirable to include the effect of combustor non-uniformities and flow gradients in order to enhance the accuracy of the aerodynamics and heat transfer predictions on the nozzle guide vanes and downstream turbine blades. The present work is the continuation of steady and quasi-unsteady studies performed previously by the authors. A fully unsteady nonlinear approach, also referred to as sliding mesh, is now used to investigate a first HPT stage and the impact of realistic non-uniformities and flow gradients found along the exit plane of a gas turbine combustor. Two Turbine Inlet Boundary Conditions (TIBC) are investigated. Simulations using a two-dimensional TIBC dependant on both the radial and circumferential directions are performed and compared to baseline analyses, where the previous two-dimensional TIBC is circumferentially averaged in order to generate inlet boundary conditions dependant only on the radial direction. The two elements included in the present work, combustor pitchwise non-uniformities and full unsteady blade row interactions are shown to: (1) alter the gas temperature profile predictions up to ±5%; (2) modify the surface temperature predictions by ±8% near the trailing edge of the vane suction side; (3) increase the overall pressure losses by roughly 1%, and (4) modified the ingestion behavior of the purge cavity flow. In addition, keeping in mind the tradeoff between improved predictions and computational cost, the use of an unsteady sliding mesh formulation, instead of a quasiunsteady frozen gust, reveals the importance of the two-way unsteady coupling between adjacent blade rows for temperature and pressure predictions.

Knowledge Sharing: Two-Dimensional Motivation Perspective and the Role of Demographic Variables

2011 ◽  
Vol 10 (02) ◽  
pp. 135-149 ◽  
Author(s):  
Aamir Amin ◽  
Mohd Fadzil Hassan ◽  
Mazeyanti Bt. Mohd Ariffin ◽  
Mobashar Rehman
Keyword(s):  
Individual Differences ◽  
Intrinsic Motivation ◽  
Knowledge Sharing ◽  
Extrinsic Motivation ◽  
Oil And Gas ◽  
Research Work ◽  
Demographic Variables ◽  
Two Dimensional ◽  
Extrinsic Rewards ◽  
The Impact

Knowledge Management (KM) efforts cannot be successful unless employees open their minds to share their valuable knowledge. Knowledge sharing is a voluntary act which requires an individual's motivation. Based on the notion that an individual's motivation is of two types, namely intrinsic and extrinsic, a framework of intrinsic and extrinsic motivators of knowledge sharing was presented at the International Symposium on Information Technology (ITSIM) in June 2010, in Kuala Lumpur Malaysia. There is a lack of research work which attempts to understand knowledge sharing motivation from intrinsic as well as extrinsic motivational perspective. Hence, the proposed framework incorporated extrinsic rewards, representing extrinsic motivation, and Organisation Citizenship Behaviour (OCB), representing intrinsic motivation, in Theory of Reasoned Action (TRA). Apart from understanding the individual's knowledge sharing motivation from a two-dimensional motivation perspective, the primary aim of this study is to extend the framework proposed in ITSIM'10 by adding demographic variable as a moderating variable. This will help to understand individual differences in knowledge sharing behaviour. At the same time, the study will present the results of ITSIM paper in detail. This study has used training institutes of an oil and gas company in Malaysia as a case. The proposed framework will overcome the research gaps in the literature by re-analysing the impact of extrinsic rewards, OCB and demographic variables on knowledge sharing. To test six major and, in total, 19 hypotheses, the questionnaire method was used to gather data from the trainers and facilitators at three training institutes of the oil and gas company. The data was analysed by using multi-regression technique. The results have shown that intrinsic motivation, represented by OCB in this study, is one of the strongest motivating factors for knowledge sharing behaviour, whereas extrinsic motivation, represented by extrinsic rewards in this study, has a moderate effect on an individual's knowledge sharing intention. The results have also shown that individuals differ in manifesting their knowledge sharing intention into behaviour based on their gender and education level, whereas there is no difference among individuals with different experience levels in manifesting their knowledge sharing intention into behaviour. The study will help to understand the individual's knowledge sharing motivation from intrinsic as well as extrinsic motivational perspectives and, at the same time, individual differences in knowledge sharing behaviour. It will aid the managers at training institutes to promote knowledge sharing in their organisations.

scholarly journals Two-dimensional model of wave-induced response of seabed around permeable submerged breakwater

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983080 ◽  
Author(s):  
Richard Asumadu ◽  
Ji-Sheng Zhang ◽  
Osei-Wusuansa Hubert ◽  
Alex Baffour Akoto
Keyword(s):  
Dynamic Response ◽  
Navier Stokes ◽  
Induced Response ◽  
Two Dimensional ◽  
Navier Stokes Equation ◽  
Structure Variation ◽  
Submerged Breakwater ◽  
Response Status ◽  
Wave Induced ◽  
The Impact

This article focuses on a two-dimensional numerical model established to determine the seabed dynamic response in the region of a permeable submerged breakwater. The wave motion in this article is governed by the volume-averaged Reynolds-averaged Navier–Stokes equation, whereas Biot’s poro-elastic equation determines the seabed foundation. The water surface is recorded using the volume of fluid technique. In this study, the results for the two-dimensional seabed dynamic response for both the consolidation status and the dynamic wave-induced response status for the seabed foundation coupled with submerged breakwater are illustrated. The numerical results examined from the dynamic pore pressure, the effective stresses, the shear stress, and the seabed soil displacements revealed that the impact of dynamic response at the offshore zone/seaward on the seabed foundation is more developed than at the onshore zone/harbor side. Parametric results analysis as regards the effect of the wave, the seabed, and the submerged breakwater structure variation significantly affected the seabed foundation response coupled with the breakwater structure. The numerical outcome on the liquefaction potential shows that the seabed foundation is more seemingly to liquefy and happen approximately at the toe of the submerged breakwater under the wave loading.

scholarly journals An Integrated Design Strategy for the Urban Regeneration of West Bay, Business District of Doha (State of Qatar)

Designs ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 55
Author(s):  
Sarah M. Al-Thani ◽  
Raffaello Furlan
Keyword(s):  
Land Use ◽  
Public Transportation ◽  
Oil And Gas ◽  
Integrated Design ◽  
Gas Production ◽  
Light Rail ◽  
Oil And Gas Production ◽  
Negative Impacts ◽  
Business District ◽  
The Impact

Emergent communities have integrated land use and transportation plan based on transit-oriented developments (TODs) and light rail transit with the sole purpose to enliven and redevelop the constructed environment. Doha has undergone some major transformation in urban growth context due to surge in the economy instigated by oil and gas production. It is noticed that the rapid growth has led to negative impacts in terms of urban design, connectivity, and transportation. It is essential to understand the impact of the TOD model with regards to the challenges and approaches in terms of planning procedures and tactics. The purpose of TOD module is to facilitate access for public transportation and to enable transit commutation which is a missing aspect in the current setting. TODs support and enable sustainable urbanism by revitalizing the livability through integration of land use schemes in the city. This paper focuses on bringing together TOD livability approaches within West Bay, the business district of Doha and its adjacent surroundings. The objective of this research is to assess the livability in West Bay with the implementation of the TOD model. The research findings help to revisit the design and application of TOD models and to enhance the livable conditions for its occupants. The finding suggests a design model based on livability, compactness, public realms, walkability, and accessibility.

scholarly journals Computer Simulation of Water Flow Animation Based on Two-Dimensional Navier-Stokes Equations

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Rushi Cao ◽  
Ruyun Cao
Keyword(s):  
Computer Graphics ◽  
Boundary Conditions ◽  
Water Flow ◽  
Stokes Equations ◽  
Simulation Method ◽  
Fluid Simulation ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equation ◽  
Navier Stokes Equations

Simulation of water flow animation is a significant and challenging subject in computer graphics. With the continuous development of computational fluid dynamics and computer graphics, many more effective simulation methods have been developed, and fluid animation simulation has developed rapidly. In order to obtain realistic flow animation, one of the key aspects is to simulate flow motion. Based on the two-dimensional Navier-Stokes equations, a mathematical model is established to solve the boundary conditions required by the physical flow field of water. The coordinate transformation formula is introduced to transform the irregular physical area into a regular square calculation area, and then, the specific expressions of the liberalized Navier-Stokes equation, continuity equation, pressure Poisson equation, and dimensionless boundary conditions are given. Using animation software to sequence graphics and images of all kinds of control and direct operation of the relevant instructions, through the computer technology to simulate the flow of animation, based on the stability of fluid simulation method and simulation efficiency, so as to make realistic flow animation. The results show that FluidsNet has considerable performance in accelerating large scene animation simulation on the basis of ensuring the rationality of prediction, and the motion of water wave is realistic. The application of computer successfully simulates water flow.

scholarly journals Study proposal of the impact of gas flaring on health of communities in Delta state Nigeria

2021 ◽  
Vol 7 (9) ◽  
pp. 468
Author(s):  
Nkemdilim Obi ◽  
Phillip Bwititi ◽  
Ezekiel Nwose
Keyword(s):  
Human Health ◽  
Oil And Gas ◽  
Environmental Concern ◽  
African Countries ◽  
Gas Flaring ◽  
Global Environmental ◽  
Oil And Gas Operations ◽  
Sub Saharan ◽  
Negative Impacts ◽  
The Impact

<p class="abstract">Gas flaring is the continuous discharge of gaseous fuel into the atmosphere during oil and gas operations. Over the past years, there has been an increased concern of the impact of gas flaring on the environment and recently on human health. The impact of gas flaring in Niger Delta, Nigeria is of local and global environmental concern. The uncontrolled and wasteful flaring of gas has caused negative impacts on the flora, fauna and human health and livelihood in the region. Reports indicate that gas flaring in Nigeria contributed more greenhouse gases (GHGs) such as carbon dioxide, methane, nitrous oxide, chlorofluorocarbons to the atmosphere than the combined contribution of gas flaring on GHGs in the Sub-Saharan African countries. The GHGs emitted during gas flaring contribute significantly to global warming which may result in sea level rise and hasten the effects of climate change. Gas flaring, commonly carried out by oil exploration companies in Nigeria poses a hazard to the health of populations and environment by pollution, warming and release of GHGs. This study seeked to identify the risks associated with gas flaring in relation to human health in Delta region of  Nigeria.</p>

scholarly journals One method to determine the solution values at the boundary for the vertical two-dimensional equation system

1998 ◽  
Vol 20 (3) ◽  
pp. 24-36
Author(s):  
Tran Gia Lich
Keyword(s):  
Boundary Conditions ◽  
Stokes Equations ◽  
Equation System ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Dimensional Equation

In this paper, the boundary conditions for modified Navier-Stokes equations system are presented, and the complementary equations on the boundaries are established.

scholarly journals The boundary conditions used for modeling tidal picture in the Gulf of Tonkin

1994 ◽  
Vol 16 (4) ◽  
pp. 37-43
Author(s):  
Do Ngoc Quynh ◽  
Pham Van Ninh ◽  
Nguyen Thi Viet Lien
Keyword(s):  
Boundary Conditions ◽  
Sea Level ◽  
Equation System ◽  
Two Dimensional ◽  
Coast Line ◽  
Venant Equation ◽  
Tidal Harmonic ◽  
Gulf Of Tonkin

The two dimensional Saint-Venant equation system is used for tidal calculation in the Gulf of Tonkin with the impermeability given at coastal line and a variation of sea level given at liquid boundaries. It is clear that data at liquid boundaries usually are very rare, while at the coast of the gulf there is a lot of data of tidal harmonic constituents. In the paper the problem how to use these constituents at coast line in modelling for raising up accuracy of the solution is considered.

Sign in / Sign up

Export Citation Format

Share Document