Physical Modeling and Computational Techniques for Thermal and Fluid-dynamics

2022 ◽  
Author(s):  
Maurizio Bottoni
Keyword(s):  
Fluid Dynamics ◽  
Physical Modeling ◽  
Computational Techniques

The Application of Computational Modeling to Pharmaceutical Materials Science

MRS Bulletin ◽  
2006 ◽  
Vol 31 (11) ◽  
pp. 900-904 ◽  
Author(s):  
Carl Wassgren ◽  
Jennifer Sinclair Curtis
Keyword(s):  
Fluid Dynamics ◽  
Computational Modeling ◽  
Development Process ◽  
Materials Science ◽  
Dosage Forms ◽  
Computational Techniques ◽  
Drug Development Process ◽  
Element Analysis ◽  
Pharmaceutical Dosage Forms ◽  
Pharmaceutical Materials

AbstractComputational modeling is a ubiquitous technique in materials science, but until recently this approach has not been widely applied to the drug development process. The formation of particles, their kinematics, and their response to processing stresses are increasingly being studied using computational techniques (computational fluid dynamics and discrete element analysis). These computational techniques can be predictive tools to guide scientists who are designing pharmaceutical dosage forms with specific macroscopic properties. This article gives an overview of the types of computational methods that are used in pharmaceutical materials science and provides examples of their application to some problems from the literature and the authors' own work.

Automatic Differentiation of the General-Purpose Computational Fluid Dynamics Package FLUENT

2006 ◽  
Vol 129 (5) ◽  
pp. 652-658 ◽  
Author(s):  
Christian H. Bischof ◽  
H. Martin Bücker ◽  
Arno Rasch ◽  
Emil Slusanschi ◽  
Bruno Lang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Automatic Differentiation ◽  
General Purpose ◽  
Computational Techniques ◽  
Software Packages ◽  
Broad Variety ◽  
Industrial Software ◽  
Crucial Ingredient ◽  
Numerical Approaches

Derivatives are a crucial ingredient to a broad variety of computational techniques in science and engineering. While numerical approaches for evaluating derivatives suffer from truncation error, automatic differentiation is accurate up to machine precision. The term automatic differentiation comprises a set of techniques for mechanically transforming a given computer program to another one capable of evaluating derivatives. A common misconception about automatic differentiation is that this technique only works on local pieces of fairly simple code. Here, it is shown that automatic differentiation is not only applicable to small academic codes, but scales to advanced industrial software packages. In particular, the general-purpose computational fluid dynamics software package FLUENT is transformed by automatic differentiation.

Uptake of Soluble Gases in the Entire Respiratory Systems of Rats and Humans Using Transient CFD/PBPK Models

2013 ◽  
Author(s):  
S. Kabilan ◽  
A. Kuprat ◽  
D. Einstein ◽  
J. Carson ◽  
R. Jacob ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Hydrogen Sulfide ◽  
Three Dimensional ◽  
Aerosol Deposition ◽  
Water Soluble ◽  
Computational Techniques ◽  
Nasal Airways ◽  
Cfd Models ◽  
Pbpk Models ◽  
Computational Fluid Dynamics Cfd

With the advancement of experimental and computational techniques, three-dimensional (3D) computational fluid dynamics (CFD) airflow models of the respiratory system have increasingly been used to evaluate aerosol deposition, gas exchange and airflow characteristics under various physiological and/or disease conditions. One specific application that is emerging in the field of toxicology is assessing the risk for exposure to highly reactive, water-soluble gases and vapors including formaldehyde, acetaldehyde, hydrogen sulfide, and acrolein by coupling CFD models of nasal airways of rats and humans to physiological based pharmacokinetic (PBPK) models.

scholarly journals Trim Influence on Kriso Container Ship (KCS): An Experimental and Numerical Study

2017 ◽  
Author(s):  
Emil Shivachev ◽  
Mahdi Khorasanchi ◽  
Alexander H. Day
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Study ◽  
Computational Cost ◽  
Breaking Waves ◽  
Computational Techniques ◽  
Container Ship ◽  
Towing Tank ◽  
Operational Life ◽  
Computational Fluid Dynamics Cfd

There has been a lot of interest in trim optimisation to reduce fuel consumption and emissions of ships. Many existing ships are designed for a single operational condition with the aim of producing low resistance at their design speed and draft with an even keel. Given that a ship will often sail outside this condition over its operational life and moreover some vessels such as LNG carriers return in ballast condition in one leg, the effect of trim on ships resistance will be significant. Ship trim optimization analysis has traditionally been done through towing tank testing. Computational techniques have become increasingly popular for design and optimization applications in all engineering disciplines. Computational Fluid Dynamics (CFD), is the fastest developing area in marine fluid dynamics as an alternative to model tests. High fidelity CFD methods are capable of modelling breaking waves which is especially crucial for trim optimisation studies where the bulbous bow partially emerges or the transom stern partially immerses. This paper presents a trim optimization study on the Kriso Container Ship (KCS) using computational fluid dynamics (CFD) in conjunction with towing tank tests. A series of resistance tests for various trim angles and speeds were conducted at 1:75 scale at design draft. CFD computations were carried out for the same conditions with the hull both fixed and free to sink and trim. Dynamic sinkage and trim add to the computational cost and thus slow the optimisation process. The results obtained from CFD simulations were in good agreement with the experiments. After validating the applicability of the computational model, the same mesh, boundary conditions and solution techniques were used to obtain resistance values for different trim conditions at different Froude numbers. Both the fixed and free trim/sinkage models could predict the trend of resistance with variation of trim angles; however the fixed model failed to measure the absolute values as accurately as the free model. It was concluded that a fixed CFD model, although computationally faster and cheaper, can find the optimum trim angle but cannot predict the amount of savings with very high accuracy. Results concerning the performance of the vessel at different speeds and trim angles were analysed and optimum trim is suggested.

Fluid-Structure Interaction Simulations of Parachute Deployment and Inflation

2021 ◽  
Author(s):  
Liwu Wang ◽  
Mingzhang Tang ◽  
Yu Liu ◽  
Sijun Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Structure Interaction ◽  
Computational Approach ◽  
Computational Techniques ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Structure Dynamics ◽  
Computational Structure ◽  
Membrane Wrinkling

Abstract The numerical simulation of the parachute deployment/inflation process involves fluid structure interaction problems, the inherent complexities in the fluid structure interaction have been posing several computational challenges. In this paper a high fidelity Eulerian computational approach is proposed for the simulation of parachute deployment/inflation. Unlike the arbitrary Eulerian Lagrangian (ALE) method widely employed in this area, the Eulerian computational approach is established on three computational techniques: computational fluid dynamics, computational structure dynamics and computational moving boundary. A set of stationary, non-deforming Cartesian grids is adopted in our computational fluid dynamics, our computational structure dynamics is enhanced by non-linear finite element method and membrane wrinkling algorithm, instead of conventional computational mesh dynamics, an immersed boundary method is employed to avoid insurmountable poor grid quality brought in by moving mesh approaches. To validate the proposed numerical approach the deployment/inflation of C-9 parachute is simulated using our approach and the results show similar characteristics compared with experimental results and previous literature. The computed results have demonstrated the proposed method to be a useful tool for analyzing dynamic parachute deployment and subsequent inflation.

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