Liver Radioembolization: An Analysis of Parameters that Influence the Catheter-Based Particle-Delivery via CFD

2020 ◽  
Vol 27 (10) ◽  
pp. 1600-1615 ◽  
Author(s):  
Jorge Aramburu ◽  
Raúl Antón ◽  
Alejandro Rivas ◽  
Juan C. Ramos ◽  
Bruno Sangro ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Particle Distribution ◽  
Numerical Approach ◽  
Radioactive Microspheres ◽  
Tumor Bearing ◽  
Hemodynamic Pattern ◽  
Valuable Treatment ◽  
Catheter Tip ◽  
Radiation Induced ◽  
Computational Fluid Dynamics Cfd

Radioembolization (RE) is a valuable treatment for liver cancer. It consists of administering radioactive microspheres by an intra-arterially placed catheter with the aim of lodging these microspheres, which are driven by the bloodstream, in the tumoral bed. Even though it is a safe treatment, some radiation-induced complications may arise. In trying to detect or solve the possible incidences that cause nontarget irradiation, simulating the particle- hemodynamics in hepatic arteries during RE by computational fluid dynamics (CFD) tools has become a valuable approach. This paper reviews the parameters that influence the outcome of RE and that have been studied via numerical simulations. In this numerical approach, the outcome of RE is regarded as successful if particles reach the artery branches that feed tumor-bearing liver segments. Up to 10 parameters have been reviewed. The variation of each parameter actually alters the hemodynamic pattern in the vicinities of the catheter tip and locally alters the incorporation of the particles into the bloodstream. Therefore, in general, the local influences of these parameters should result in global differences in terms of particle distribution in the hepatic artery branches. However, it has been observed that under some (qualitatively described) appropriate conditions where particles align with blood streamlines, the local influence resulting from a variation of a given parameter vanishes and no global differences are observed. Furthermore, the increasing number of CFD studies on RE suggests that numerical simulations have become an invaluable research tool in the study of RE.

scholarly journals Radiation-induced lung fibrosis in a tumor-bearing mouse model is associated with enhanced Type-2 immunity

2015 ◽  
Vol 57 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Jing Chen ◽  
Yacheng Wang ◽  
Zijie Mei ◽  
Shimin Zhang ◽  
Jie Yang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Lung Fibrosis ◽  
Tumor Bearing Mouse ◽  
Tumor Bearing ◽  
Type 2 Immunity ◽  
Radiation Induced

Turbine Airfoil Heat Transfer Predictions Using CFD

2005 ◽  
Author(s):  
Anil K. Tolpadi ◽  
James A. Tallman ◽  
Lamyaa El-Gabry
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Design System ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Airfoils ◽  
Typical Design

Conventional heat transfer design methods for turbine airfoils use 2-D boundary layer codes (BLC) combined with empiricism. While such methods may be applicable in the mid span of an airfoil, they would not be very accurate near the end-walls and airfoil tip where the flow is very three-dimensional (3-D) and complex. In order to obtain accurate heat transfer predictions along the entire span of a turbine airfoil, 3-D computational fluid dynamics (CFD) must be used. This paper describes the development of a CFD based design system to make heat transfer predictions. A 3-D, compressible, Reynolds-averaged Navier-Stokes CFD solver with k-ω turbulence modeling was used. A wall integration approach was used for boundary layer prediction. First, the numerical approach was validated against a series of fundamental airfoil cases with available data. The comparisons were very favorable. Subsequently, it was applied to a real engine airfoil at typical design conditions. A discussion of the features of the airfoil heat transfer distribution is included.

scholarly journals Numerical simulation of dispersion of ammonia in industry space using the ANSYS

2018 ◽  
Vol 247 ◽  
pp. 00044
Author(s):  
Zdzisław Salamonowicz
Keyword(s):  
Numerical Simulations ◽  
Roughness Parameter ◽  
Numerical Approach ◽  
Chemical Equipment ◽  
Empirical Models ◽  
Average Roughness ◽  
Danger Zone ◽  
Industrial Installation ◽  
Heavy Gas ◽  
Selection Of

The article presents issues related to numerical simulations of the spread of dangerous substances in the air after emergency release from industrial installation. The work contains the results of numerical simulations of dispersion of ammonia and chlorine after emergency release made by using the ANSYS program, validated based on commonly used models: Gauss and heavy gas. Validation of experimental results based on research and empirical models allowed the selection of boundary parameters and the implementation of dispersion modelling in 3-d space taking into account technical infrastructure. Existing empirical models include terrain obstacles in the form of average roughness parameter, which is shown in general by the range of the danger zone without local topographic conditions. The numerical approach to modelling, in contrast to empirical models, allows to more accurately show the physicochemical phenomena occurring after release in 3-d space, both in the area around the chemical equipment and the buildings along the dangerous substance cloud.

Drag Reduction Through Changes in Cabin Geometry and Trailer Gap of Heavy-Duty Trucks

Volume 1 ◽  
2004 ◽  
Author(s):  
M. Lakshman ◽  
K. Aung
Keyword(s):  
Numerical Simulations ◽  
Aerodynamic Drag ◽  
Cost Savings ◽  
Vehicle Speed ◽  
Fuel Cost ◽  
Heavy Duty ◽  
Cross Sectional ◽  
Computational Fluid Dynamics Cfd ◽  
Imported Oil ◽  
Fuel Costs

Reduction of aerodynamic drag of heavy-duty trucks can significantly save fuel costs and US dependence on the imported oil. Reduction of aerodynamic drag by 30% can result in fuel cost savings in billions of dollars every year. Aerodynamic drag of truck depends on the frontal cross-sectional area and the speed of the vehicle. In addition, the gap between the cabin and the trailer significantly affect the drag of the truck. This paper investigates how changes in the cabin geometry and the trailer gap can reduce the aerodynamic drag using numerical simulations. The numerical simulations were carried out using Computational Fluid Dynamics (CFD) software, CFX-5.5, from AEA Technologies (now owned by ANSYS). Effects of vehicle speed, cabin geometry, and trailer gap on the aerodynamic drag were investigated.

Hydraulic Improvement to Eliminate S-Shaped Curve in Pump Turbine

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Jun-lian Yin ◽  
De-zhong Wang ◽  
Xian-zhu Wei ◽  
Le-qin Wang
Keyword(s):  
Design Method ◽  
Numerical Approach ◽  
Problem Analysis ◽  
Hydraulic Loss ◽  
Blade Loading ◽  
Loss Analysis ◽  
Hydraulic Design ◽  
Computational Fluid Dynamics Cfd ◽  
Inverse Design Method ◽  
Pumped Storage

For pump turbines, an S-shaped curve can lead to failures in synchronization. To improve the hydraulic design, the component that is responsible for the formation of the S-shaped curve was identified by a hydraulic loss analysis using previous computational fluid dynamics (CFD) results, which indicates that the formation of the S-shaped curve can be ascribed to the runner. To improve the hydraulic design of the runner, a simple numerical approach for direct problem analysis was proposed, based on the blade-loading distributions of runners with and without an S-shaped curve, and directly analyzed. It was implied from the differences in the blade-loading distributions that, when the meridional passage was broadened, the formation of the S-shaped curve was suppressed. To validate this, two runners with different meridional sections were designed by means of the inverse design method. Through model tests, it was verified that the S-shaped curve was eliminated completely and the performance curve of the modified hydraulic model satisfied the requirements for safe operation in a pumped storage plant.

scholarly journals Analysis of Cyclist’s Drag on the Aero Position Using Numerical Simulations and Analytical Procedures: A Case Study

2020 ◽  
Vol 17 (10) ◽  
pp. 3430 ◽  
Author(s):  
Pedro Forte ◽  
Daniel A. Marinho ◽  
Pantelis T. Nikolaidis ◽  
Beat Knechtle ◽  
Tiago M. Barbosa ◽  
...  
Keyword(s):  
Linear Regression ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Paired Samples ◽  
Computational Fluid Dynamics Cfd ◽  
Analytical Procedures ◽  
Previous Training ◽  
Very High

Background: Resistance acting on a cyclist is a major concern among the cycling fraternity. Most of the testing methods require previous training or expensive equipment and time-consuming set-ups. By contrast, analytical procedures are more affordable and numerical simulations are perfect for manipulating and controlling inputs. The aim of this case study was to compare the drag of a cyclist in the aero position as measured using numerical simulation and analytical procedures. Methods: An elite male cyclist (65 kg in mass and 1.72 m in height) volunteered to take part in this research. The cyclist was wearing his competition gear, helmet and bicycle. A three-dimensional model of the bicycle and cyclist in the aero position was obtained to run the numerical simulations. Computational fluid dynamics (CFD) and a set of analytical procedures were carried out to assess drag, frontal area and drag coefficient, between 1 m/s and 22 m/s, with increments of 1 m/s. The t-test paired samples and linear regression were selected to compare, correlate and assess the methods agreement. Results: No significant differences (t = 2.826; p = 0.275) between CFD and analytical procedures were found. The linear regression showed a very high adjustment for drag (R2 = 0.995; p < 0.001). However, the drag values obtained by the analytical procedures seemed to be overestimated, even though without effect (d = 0.11). Conclusions: These findings suggest that drag might be assessed using both a set of analytical procedures and CFD.

scholarly journals Estimates Related to the Extended Spectral Control of the Wave Equation

2018 ◽  
Vol 10 (4) ◽  
pp. 156
Author(s):  
Cheikh Seck ◽  
Abdoulaye Sène ◽  
Mary Niane
Keyword(s):  
Wave Equation ◽  
Numerical Simulations ◽  
Numerical Approach ◽  
Regular Domain ◽  
Spectral Control

In this work, we show through a numerical approach the extended spectral controllability of the wave equation over a portion of a regular domain, and that the spectrum obtained is quasi-symmetrical. Numerical simulations also verify the analytical estimates demonstrated in Niane and al. $[4]$ and the graphic illustrations relating to this spectral controllability were done.

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