Christian Yarin - Academia.edu (original) (raw)

Uploads

Papers by Christian Yarin

Research paper thumbnail of On the influence of the particles–fluid interaction on the turbulent diffusion in a suspension

International Journal of Multiphase Flow, 2002

A theory for the turbulent diffusion of particles suspended in an incompressible fluid is present... more A theory for the turbulent diffusion of particles suspended in an incompressible fluid is presented. Special attention is paid to the influence on the turbulent diffusion of the two-way coupling between the carrier fluid and the dispersed particles. Also the influence of the hydrodynamic interaction between the particles and the influence of the finite-particle size are investigated. It is shown that the influence of the particles-fluid interaction and of the finite-particle size are significant. The hydrodynamic interaction between the particles appears to be negligible up to a volume fraction of 0.1. Ó

Research paper thumbnail of Oblique penetration of a rigid projectile into a thick elastic–plastic target: theory and experiment

International Journal of Impact Engineering, 1999

A model of oblique penetration of a rigid projectile into a thick elastic–plastic target has been... more A model of oblique penetration of a rigid projectile into a thick elastic–plastic target has been developed (Roisman et al., Int J Impact Engng 1997; 19: 769–95) which incorporates stress-free boundary conditions at the rear surface of the target. The main objective of the present work is to validate the theoretical model by comparison with new experimental results for normal and oblique penetration of a rigid projectile into a thick plate of Al 6061-T651. Good agreement between theory and experiment is exhibited for the projectile residual velocity and the crater shape.

Research paper thumbnail of The beads-on-string structure of viscoelastic threads

Journal of Fluid Mechanics, 2006

By adding minute concentrations of a high molecular weight polymer, liquid jets or bridges collap... more By adding minute concentrations of a high molecular weight polymer, liquid jets or bridges collapsing under the action of surface tension develop a characteristic shape of uniform threads connecting spherical fluid drops. In this paper, high-precision measurements of this beads-on-string structure are combined with a theoretical analysis of the limiting case of large polymer relaxation times, for which the evolution can be divided into two distinct regimes. This excludes the very late stages of the evolution, for which the polymers have become fully stretched. For times smaller than the polymer relaxation time, over which the beads-on-string structure develops, we give a simplified local description, which still contains the full complexity of the problem. At times much larger than the relaxation time, we show that the solution consists of exponentially thinning threads connecting almost spherical drops. Both experiment and theoretical analysis of a one-dimensional model equation reveal a self-similar structure of the corner where a thread is attached to the neighbouring drops.

Research paper thumbnail of Shear and extensional investigations in solutions of grafted/ungrafted amylopectin and polyacrylamide

Journal of Applied Polymer Science, 1999

Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGIS... more Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGISLACION AMBIENTAL PROFESOR : PERICHE YARLEQUE ALUMNAS : o AVILA RAMOS GERALDINE ALEXANDRA o ESPILCO HUAMANI YESENIA LISETTE CICLO : IX TEMA: CONTAMINACIÓN POR RUIDO PROLOGO O INTRODUCCION: Se llama contaminación acústica (o contaminación auditiva) al exceso de sonido que altera las condiciones normales del ambiente en una determinada zona. Si bien el ruido no se acumula, traslada o mantiene en el tiempo como las otras contaminaciones, también puede causar grandes daños en la calidad de vida de las personas si no se controla bien o adecuadamente.

Research paper thumbnail of Model for ballistic fragmentation and behind-armor debris

International Journal of Impact Engineering, 2000

The fracture of the target and projectile during normal penetration is described using a model of... more The fracture of the target and projectile during normal penetration is described using a model of chaotic disintegration modifying the theory of chaotic disintegration of liquids. The radius of the locally smallest fragment is calculated equating its kinetic energy of deformation with its surface energy of fracture. The probability of lacunae opening in the target and projectile materials increases near the target/projectile interface. The percolation threshold for this probability determines the boundary of the fractured zone. When this fractured zone reaches the rear surface of the target the fragments can leave it. Mass distribution of the fragments was calculated with the help of percolation theory. Then, the shape of the debris cloud and the direction, velocity and range of its propagation are calculated to estimate vulnerability behind the perforated target.The calculations were compared with results of normal impact experiments performed with tungsten sinter alloy rods (D=20 mm, L/D=6) against 40 and 70 mm rolled homogeneous armor (RHA) at an impact velocity of 1700 m/s and . For observation of the bulging, breakup and fragmentation of the bulge as well as debris cloud formation and expansion, flash X-ray and laser stroboscope techniques have been applied. From the X-ray photographs and soft recovery tests the shape of the debris cloud and velocity field of the fragments as well as the fragment number and mass distributions have been determined, respectively. The calculations predict well the experimental data.

Research paper thumbnail of trabajo contaminacion Sonora 1

Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGIS... more Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGISLACION AMBIENTAL PROFESOR : PERICHE YARLEQUE ALUMNAS : o AVILA RAMOS GERALDINE ALEXANDRA o ESPILCO HUAMANI YESENIA LISETTE CICLO : IX TEMA: CONTAMINACIÓN POR RUIDO PROLOGO O INTRODUCCION: Se llama contaminación acústica (o contaminación auditiva) al exceso de sonido que altera las condiciones normales del ambiente en una determinada zona. Si bien el ruido no se acumula, traslada o mantiene en el tiempo como las otras contaminaciones, también puede causar grandes daños en la calidad de vida de las personas si no se controla bien o adecuadamente.

Research paper thumbnail of On the influence of the particles–fluid interaction on the turbulent diffusion in a suspension

International Journal of Multiphase Flow, 2002

A theory for the turbulent diffusion of particles suspended in an incompressible fluid is present... more A theory for the turbulent diffusion of particles suspended in an incompressible fluid is presented. Special attention is paid to the influence on the turbulent diffusion of the two-way coupling between the carrier fluid and the dispersed particles. Also the influence of the hydrodynamic interaction between the particles and the influence of the finite-particle size are investigated. It is shown that the influence of the particles-fluid interaction and of the finite-particle size are significant. The hydrodynamic interaction between the particles appears to be negligible up to a volume fraction of 0.1. Ó

Research paper thumbnail of Oblique penetration of a rigid projectile into a thick elastic–plastic target: theory and experiment

International Journal of Impact Engineering, 1999

A model of oblique penetration of a rigid projectile into a thick elastic–plastic target has been... more A model of oblique penetration of a rigid projectile into a thick elastic–plastic target has been developed (Roisman et al., Int J Impact Engng 1997; 19: 769–95) which incorporates stress-free boundary conditions at the rear surface of the target. The main objective of the present work is to validate the theoretical model by comparison with new experimental results for normal and oblique penetration of a rigid projectile into a thick plate of Al 6061-T651. Good agreement between theory and experiment is exhibited for the projectile residual velocity and the crater shape.

Research paper thumbnail of The beads-on-string structure of viscoelastic threads

Journal of Fluid Mechanics, 2006

By adding minute concentrations of a high molecular weight polymer, liquid jets or bridges collap... more By adding minute concentrations of a high molecular weight polymer, liquid jets or bridges collapsing under the action of surface tension develop a characteristic shape of uniform threads connecting spherical fluid drops. In this paper, high-precision measurements of this beads-on-string structure are combined with a theoretical analysis of the limiting case of large polymer relaxation times, for which the evolution can be divided into two distinct regimes. This excludes the very late stages of the evolution, for which the polymers have become fully stretched. For times smaller than the polymer relaxation time, over which the beads-on-string structure develops, we give a simplified local description, which still contains the full complexity of the problem. At times much larger than the relaxation time, we show that the solution consists of exponentially thinning threads connecting almost spherical drops. Both experiment and theoretical analysis of a one-dimensional model equation reveal a self-similar structure of the corner where a thread is attached to the neighbouring drops.

Research paper thumbnail of Shear and extensional investigations in solutions of grafted/ungrafted amylopectin and polyacrylamide

Journal of Applied Polymer Science, 1999

Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGIS... more Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGISLACION AMBIENTAL PROFESOR : PERICHE YARLEQUE ALUMNAS : o AVILA RAMOS GERALDINE ALEXANDRA o ESPILCO HUAMANI YESENIA LISETTE CICLO : IX TEMA: CONTAMINACIÓN POR RUIDO PROLOGO O INTRODUCCION: Se llama contaminación acústica (o contaminación auditiva) al exceso de sonido que altera las condiciones normales del ambiente en una determinada zona. Si bien el ruido no se acumula, traslada o mantiene en el tiempo como las otras contaminaciones, también puede causar grandes daños en la calidad de vida de las personas si no se controla bien o adecuadamente.

Research paper thumbnail of Model for ballistic fragmentation and behind-armor debris

International Journal of Impact Engineering, 2000

The fracture of the target and projectile during normal penetration is described using a model of... more The fracture of the target and projectile during normal penetration is described using a model of chaotic disintegration modifying the theory of chaotic disintegration of liquids. The radius of the locally smallest fragment is calculated equating its kinetic energy of deformation with its surface energy of fracture. The probability of lacunae opening in the target and projectile materials increases near the target/projectile interface. The percolation threshold for this probability determines the boundary of the fractured zone. When this fractured zone reaches the rear surface of the target the fragments can leave it. Mass distribution of the fragments was calculated with the help of percolation theory. Then, the shape of the debris cloud and the direction, velocity and range of its propagation are calculated to estimate vulnerability behind the perforated target.The calculations were compared with results of normal impact experiments performed with tungsten sinter alloy rods (D=20 mm, L/D=6) against 40 and 70 mm rolled homogeneous armor (RHA) at an impact velocity of 1700 m/s and . For observation of the bulging, breakup and fragmentation of the bulge as well as debris cloud formation and expansion, flash X-ray and laser stroboscope techniques have been applied. From the X-ray photographs and soft recovery tests the shape of the debris cloud and velocity field of the fragments as well as the fragment number and mass distributions have been determined, respectively. The calculations predict well the experimental data.

Research paper thumbnail of trabajo contaminacion Sonora 1

Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGIS... more Facultad de ingeniería ambiental y recursos naturales TEMA: CONTAMINACIÓN POR RUIDO CURSO : LEGISLACION AMBIENTAL PROFESOR : PERICHE YARLEQUE ALUMNAS : o AVILA RAMOS GERALDINE ALEXANDRA o ESPILCO HUAMANI YESENIA LISETTE CICLO : IX TEMA: CONTAMINACIÓN POR RUIDO PROLOGO O INTRODUCCION: Se llama contaminación acústica (o contaminación auditiva) al exceso de sonido que altera las condiciones normales del ambiente en una determinada zona. Si bien el ruido no se acumula, traslada o mantiene en el tiempo como las otras contaminaciones, también puede causar grandes daños en la calidad de vida de las personas si no se controla bien o adecuadamente.