Modeling Steam Dryers

2010 ◽  
Author(s):  
Dani Fadda ◽  
David Taylor ◽  
Jason Burr ◽  
Michael Sredzienski ◽  
Jeff Gardner
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steam Generator ◽  
Computational Models ◽  
Steam Flow ◽  
High Quality ◽  
Cfd Models ◽  
Full Capacity ◽  
Computational Fluid Dynamics Cfd ◽  
Very High

Nuclear steam dryers are used to reduce the moisture carryover (MCO) to levels often well below 0.1%, by weight, water in the steam. The dryers are designed to provide very high quality steam at the full capacity of the steam generator. The purpose of this paper is to present computational fluid dynamics (CFD) models of the steam flow in a generator and the decisions that are required to evaluate different designs. These computational models are successful and proven in field operations.

scholarly journals Modelling of working processes of non-contact oil free vacuum pumps by computational fluid dynamics (CFD) methods

2021 ◽  
Vol 2059 (1) ◽  
pp. 012003
Author(s):  
A Burmistrov ◽  
A Raykov ◽  
S Salikeev ◽  
E Kapustin
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Mathematical Models ◽  
Cfd Models ◽  
Ansys Cfx ◽  
Sst Turbulence Model ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamic Meshing ◽  
Comparison With Experimental Data

Abstract Numerical mathematical models of non-contact oil free scroll, Roots and screw vacuum pumps are developed. Modelling was carried out with the help of software CFD ANSYS-CFX and program TwinMesh for dynamic meshing. Pumping characteristics of non-contact pumps in viscous flow with the help of SST-turbulence model were calculated for varying rotors profiles, clearances, and rotating speeds. Comparison with experimental data verified adequacy of developed CFD models.

scholarly journals Propagation of Input Uncertainty in Presence of Model-Form Uncertainty: A Multifidelity Approach for Computational Fluid Dynamics Applications

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Jian-Xun Wang ◽  
Christopher J. Roy ◽  
Heng Xiao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Parameter Space ◽  
Uncertainty Propagation ◽  
High Fidelity ◽  
Sampling Errors ◽  
Uncertainty Distribution ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Applications

Proper quantification and propagation of uncertainties in computational simulations are of critical importance. This issue is especially challenging for computational fluid dynamics (CFD) applications. A particular obstacle for uncertainty quantifications in CFD problems is the large model discrepancies associated with the CFD models used for uncertainty propagation. Neglecting or improperly representing the model discrepancies leads to inaccurate and distorted uncertainty distribution for the quantities of interest (QoI). High-fidelity models, being accurate yet expensive, can accommodate only a small ensemble of simulations and thus lead to large interpolation errors and/or sampling errors; low-fidelity models can propagate a large ensemble, but can introduce large modeling errors. In this work, we propose a multimodel strategy to account for the influences of model discrepancies in uncertainty propagation and to reduce their impact on the predictions. Specifically, we take advantage of CFD models of multiple fidelities to estimate the model discrepancies associated with the lower-fidelity model in the parameter space. A Gaussian process (GP) is adopted to construct the model discrepancy function, and a Bayesian approach is used to infer the discrepancies and corresponding uncertainties in the regions of the parameter space where the high-fidelity simulations are not performed. Several examples of relevance to CFD applications are performed to demonstrate the merits of the proposed strategy. Simulation results suggest that, by combining low- and high-fidelity models, the proposed approach produces better results than what either model can achieve individually.

Good modelling practice in applying computational fluid dynamics for WWTP modelling

2015 ◽  
Vol 73 (5) ◽  
pp. 969-982 ◽  
Author(s):  
Edward Wicklein ◽  
Damien J. Batstone ◽  
Joel Ducoste ◽  
Julien Laurent ◽  
Alonso Griborio ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Working Group ◽  
Companion Paper ◽  
Cfd Modelling ◽  
Cfd Models ◽  
Water Association ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Applications ◽  
International Water

Computational fluid dynamics (CFD) modelling in the wastewater treatment (WWT) field is continuing to grow and be used to solve increasingly complex problems. However, the future of CFD models and their value to the wastewater field are a function of their proper application and knowledge of their limits. As has been established for other types of wastewater modelling (i.e. biokinetic models), it is timely to define a good modelling practice (GMP) for wastewater CFD applications. An International Water Association (IWA) working group has been formed to investigate a variety of issues and challenges related to CFD modelling in water and WWT. This paper summarizes the recommendations for GMP of the IWA working group on CFD. The paper provides an overview of GMP and, though it is written for the wastewater application, is based on general CFD procedures. A forthcoming companion paper to provide specific details on modelling of individual wastewater components forms the next step of the working group.

scholarly journals Computational simulation of soybean particles flow in a hopper using computational fluid dynamics (CFD) and discrete elements method (DEM)

2020 ◽  
Vol 9 (8) ◽  
pp. e448985463
Author(s):  
Jéssica Aparecida Apolinário de Paula ◽  
Érica Victor de Faria ◽  
Ana Christina Pitard Lima ◽  
José Luiz Vieira Neto ◽  
Kássia Graciele dos Santos
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computational Models ◽  
Solid Phase ◽  
Computational Simulation ◽  
Fluid Phase ◽  
Discrete Elements ◽  
Granular Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
The Subject

The hoppers are the most common structures used in storage units for agricultural products such as grains and cereals. The soybean, which is one of the most common products in Brazil spend most of their time in a hopper between the stages of picking and shipment. Problems such as damage to the hopper structures during the outflow are factors that have been the subject of studies using computational models. Computational Fluid Dynamics (CFD) has played a big role in gas-solid systems study, together with the Discrete Element Method (DEM). This method manages both fluid phase as the solid phase, which in this case is granular, through the Eulerian and Lagrangian approach. The DEM is based on the interaction between the particles and each one is separately monitored. This work aims to calibrate the parameters of the spring-dashpot model, in the granular dynamics of fluids study, which influences the contact between the soy particles in the silo. For this purpose, a comparison was made of the experimental discharge time of soybeans into a hopper, with the time resulting from 27 simulations generated by a central composite design (CCD). Through the analysis of the simulations and statistics, it was possible to identify the factors that influence whether or not the time of discharge and establish a calibration of these parameters that best describe the experimental results.

Experimental and Numerical Investigation of a Centrifugal Nozzle

2007 ◽  
Author(s):  
Jason Smith ◽  
Robert N. Eli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particulate Matter ◽  
Laboratory Experiment ◽  
Numerical Investigation ◽  
Industrial Applications ◽  
Fluid Mixing ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd

This paper reports on a laboratory experiment conducted more than 30 years ago (Eli, 1974, unpublished), and recent Computational Fluid Dynamics (CFD) investigations, focusing on the properties of a plane tangential jet produced by an apparatus called a “centrifugal nozzle.” The authors believe that the centrifugal nozzle has potential industrial applications in several areas related to fluid mixing and particulate matter suspension in mixing tanks. It is also believed that this experiment, or one similar, may provide data useful for benchmarking CFD models.

scholarly journals Computational Fluid Dynamics Modeling of Liver Radioembolization: A Review

2021 ◽  
Author(s):  
Jorge Aramburu ◽  
Raúl Antón ◽  
Macarena Rodríguez-Fraile ◽  
Bruno Sangro ◽  
José Ignacio Bilbao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Point Of View ◽  
Cfd Modeling ◽  
Dynamics Modeling ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Modeling ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
Intraarterial Therapy

AbstractYttrium-90 radioembolization (RE) is a widely used transcatheter intraarterial therapy for patients with unresectable liver cancer. In the last decade, computer simulations of hepatic artery hemodynamics during RE have been performed with the aim of better understanding and improving the therapy. In this review, we introduce the concept of computational fluid dynamics (CFD) modeling with a clinical perspective and we review the CFD models used to study RE from the fluid mechanics point of view. Finally, we show what CFD simulations have taught us about the hemodynamics during RE, the current capabilities of CFD simulations of RE, and we suggest some future perspectives.

Validation of Computational Fluid Dynamics Models for Industrial Applications

2021 ◽  
Author(s):  
Milorad B. Dzodzo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Complex Geometry ◽  
Mesh Size ◽  
Industrial Applications ◽  
Cfd Models ◽  
Long Duration ◽  
Computational Fluid Dynamics Cfd ◽  
Accident Scenarios ◽  
Dynamics Models

Abstract Validation of Computational Fluid Dynamics (CFD) models for industrial applications is more challenging due to the complex geometry and long duration and complexity of various postulated accident scenarios, resulting in different and wide ranges of length and time scales. Thus, CFD models for industrial applications are restricted to the smaller subdomains and short periods of postulated accident scenarios. Validation is most often based on the comparisons with experimental results obtained with the scaled down test facilities. Thus, the effect of scaling needs to be considered and incorporated in the validation process. During validation, valuable experience is gained related to geometry simplifications, needed mesh size, turbulence and heat transfer modeling, effects of initial and boundary conditions, different fluid thermophysical properties and interaction with other phenomena and processes. Based on the gained experience the validated CFD models are adjusted and used to simulate prototypical domains and conditions. Several examples of validations of CFD models for industrial applications are presented.

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