DC and transient models of the MSET device

2021 ◽  
Author(s):  
Assaf Peled ◽  
Ofer Amrani ◽  
Yossi Rosenwaks
Keyword(s):  
Transient Models

Transient Models to Analyze the Influence of the Air Velocity and Ducts Diameter on the Performance of Earth-Air Heat Exchangers

2016 ◽  
Vol 43 (5-6) ◽  
pp. 503-520 ◽  
Author(s):  
R. S. Brum ◽  
J. V. A. Ramalho ◽  
Luiz Alberto O. Rocha ◽  
L. A. Isoldi ◽  
E. D. dos Santos
Keyword(s):  
Heat Exchangers ◽  
Air Velocity ◽  
Transient Models

Numerical Integration of the AUSMV Scheme With a Dynamic Wellbore Temperature Model

2018 ◽  
Author(s):  
John Emeka Udegbunam ◽  
Kjell Kåre Fjelde ◽  
Dan Sui
Keyword(s):  
Dynamic Models ◽  
Drilling Fluid ◽  
Splitting Method ◽  
Isothermal Condition ◽  
Temperature Model ◽  
Two Phase ◽  
Transient Model ◽  
Flux Vector Splitting ◽  
Wellbore Temperature ◽  
Transient Models

The AUSMV scheme is a hybrid transient model derived from Advection-Upwind-Splitting Method (AUSM) and Flux Vector Splitting (FVS) method. The two-phase flow model was formulated under isothermal condition. This neglected the behavior of temperature during transient scenarios, for instance, unloading and drilling fluid circulation. In contrast to this assumption, wellbore temperature changes locally with time under such dynamic conditions. The numerical accuracy of the AUSMV scheme can be improved in two ways. The scheme can be reformulated by including energy equation in the system of governing conservation laws. This option, however, is computationally rigorous and expensive. A better alternative is to develop a separate dynamic temperature model that will calculate wellbore and formation temperatures. Then the two dynamic models — the AUSMV scheme and temperature model — are numerically coupled into a thermohydraulic simulator. The present work will include a brief introduction to the AUSMV scheme, followed by the description of the temperature model. In addition, how the two transient models are integrated will be presented. Simulation cases, demonstrating the improved modeling capability of the scheme for a drilling situation, will be shown.

Pipeline Diagnostics With Ultrasonic Meters

2016 ◽  
Author(s):  
Nicole Gailey ◽  
Noman Rasool
Keyword(s):  
Real Time ◽  
Measurement Errors ◽  
Flow Measurement ◽  
Detection System ◽  
Leak Detection ◽  
The United States ◽  
Time Data ◽  
Critical System ◽  
Detection Systems ◽  
Transient Models

Canada and the United States have vast energy resources, supported by thousands of kilometers (miles) of pipeline infrastructure built and maintained each year. Whether the pipeline runs through remote territory or passing through local city centers, keeping commodities flowing safely is a critical part of day-to-day operation for any pipeline. Real-time leak detection systems have become a critical system that companies require in order to provide safe operations, protection of the environment and compliance with regulations. The function of a leak detection system is the ability to identify and confirm a leak event in a timely and precise manner. Flow measurement devices are a critical input into many leak detection systems and in order to ensure flow measurement accuracy, custody transfer grade liquid ultrasonic meters (as defined in API MPMS chapter 5.8) can be utilized to provide superior accuracy, performance and diagnostics. This paper presents a sample of real-time data collected from a field install base of over 245 custody transfer grade liquid ultrasonic meters currently being utilized in pipeline leak detection applications. The data helps to identify upstream instrumentation anomalies and illustrate the abilities of the utilization of diagnostics within the liquid ultrasonic meters to further improve current leak detection real time transient models (RTTM) and pipeline operational procedures. The paper discusses considerations addressed while evaluating data and understanding the importance of accuracy within the metering equipment utilized. It also elaborates on significant benefits associated with the utilization of the ultrasonic meter’s capabilities and the importance of diagnosing other pipeline issues and uncertainties outside of measurement errors.

1-Node Transient Models

2015 ◽  
pp. 97-162
Author(s):  
George Sidebotham
Keyword(s):  
Transient Models

scholarly journals Gene Expression in RET/PTC3 and E7 Transgenic Mouse Thyroids: RET/PTC3 But Not E7 Tumors Are Partial and Transient Models of Human Papillary Thyroid Cancers

Endocrinology ◽  
2008 ◽  
Vol 149 (10) ◽  
pp. 5107-5117 ◽  
Author(s):  
Agnès Burniat ◽  
Ling Jin ◽  
Vincent Detours ◽  
Natacha Driessens ◽  
Jean-Christophe Goffard ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fusion Gene ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Human Thyroid ◽  
Matrix Remodeling ◽  
Biological Processes ◽  
Papillary Thyroid ◽  
Thyroid Cancers ◽  
Transient Models

We studied gene expression profiles in two mouse models of human thyroid carcinoma: the Tg-RET/PTC3 (RP3) and Tg-E7 mice. RP3 fusion gene is the most frequent mutation found in the first wave post-Chernobyl papillary thyroid cancers (PTCs). E7 is an oncoprotein derived from the human papillomavirus 16 responsible for most cervical carcinoma in women. Both transgenic mice develop thyroid hyperplasia followed by solid differentiated carcinoma in older animals. To understand the different steps leading to carcinoma, we analyzed thyroid gene expression in both strains at different ages by microarray technology. Important biological processes were differentially regulated in the two tumor types. In E7 thyroids, cell cycle was the most up-regulated process, an observation consistent with the huge size of these tumors. In RP3 thyroids, contrary to E7 tumors, several human PTC characteristics were observed: overexpression of many immune-related genes, regulation of human PTC markers, up-regulation of EGF-like growth factors and significant regulation of angiogenesis and extracellular matrix remodeling-related genes. However, similarities were incomplete; they did not concern the overall gene expression and were not conserved in old animals. Therefore, RP3 tumors are partial and transient models of human PTC. They constitute a good model, especially in young animals, to study the respective role of the biological processes shared with human PTC and will allow testing drugs targeting these validated variables.

scholarly journals DARK MATTER TO DARK ENERGY TRANSITION IN k-ESSENCE COSMOLOGIES

2005 ◽  
Vol 20 (27) ◽  
pp. 2075-2082 ◽  
Author(s):  
L. P. CHIMENTO ◽  
MÓNICA FORTE ◽  
RUTH LAZKOZ
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Kinetic Energy ◽  
Speed Of Sound ◽  
Energy Transition ◽  
Chaplygin Gas ◽  
Large Set ◽  
Generalized Chaplygin Gas ◽  
General Terms ◽  
Transient Models

We implement the transition from dark matter to dark energy in k-essence cosmologies for a very large set of kinetic functions F, in a way alternative to recent proposals which use generalized Chaplygin gas and transient models. Here we require that the pressure admits a power-law expansion around some value of the kinetic energy where the pressure vanishes. In addition, for suitable values of the parameters of the model, the speed of sound of the dark matter will be low. We first present the discussion in fairly general terms, and later consider for illustration two examples.

Assessment of the Impact of Wax Deposition in a Pre-Salt Project

2021 ◽  
Author(s):  
Nathalie Carvalho Pinheiro ◽  
Sergio Paulo Gomes Pinho
Keyword(s):  
Diffusion Coefficient ◽  
Wax Deposition ◽  
Full Field ◽  
Deposition Model ◽  
High Production ◽  
The One ◽  
Wax Deposits ◽  
Transient Models ◽  
The Impact ◽  
Production Losses

Abstract Despite pre-salt fields in Brazil usually having high production per well, one of the areas presents a reservoir with low permoporosity, which results in small flowrates with fluid temperatures during production below the one that is critical for wax deposition. The operations commonly used to remove the wax deposits are diesel soaking and pigging, which brings production losses and OPEX increase. Thus, the economic analysis should consider these events reducing the operational efficiency of production. To evaluate the production drop due to wax deposition, it was necessary to perform a loop test to determine the wax growth throughout time. With a multiphase simulator, it is possible to choose the deposition model and the diffusion coefficient that best fits the analyzed fluid. However, one of the limitations of this first analysis is the lack of data to determine the effect of the shear stripping, as the test is performed under a laminar flow. As this term plays an important role in wax growth, it was necessary to add to the simulation model the shear coefficient fitted from another pre-salt field. With this information, it will be possible to make a more reliable evaluation of the impact of wax deposition, increasing the confidence in the production curve, OPEX and NPV of the full field project. This paper shows the methodology that has been applied to evaluate the impact of wax deposition in pre-salt fields. It presents the deposition model, and its coefficients used to fit the multiphase transient models to a pre-salt field.

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