Quantum Nanoscale Flow Systems Laboratory

Nanoscale Flow Research Division

Quantum Nanoscale Flow Systems Laboratory

Concurrent Professor
Seiji
Samukawa
Associate Professor
Takashi
Tokumasu
Assistant Professor
Takuya
Mabuchi

In the flow phenomena of fluid, it is often seen that the "chemical reaction" which occurs at the atomic/molecular scale affects much on the macroscopic "diffusion phenomena" of fluids. Moreover, very light atoms, such as hydrogen, cannot be regarded as a mass point and its effect sometimes appears at the phase diagram of this substance. When we analyze the mechanism by which the characteristics appears or behaviors of nanoscale flow systems which consists of such substances, it is necessary to analyze them by the method in which the "quantum effect" of the substances is considered because the conventional molecular dynamics method cannot treat such characteristics accurately. Our laboratory treats the system in which the quantum effect of such fluid affects on the flow phenomena, and conducts research on clarification of its physical mechanism by various methods with considering the quantum effect and its application for engineering aspects.

A quantum/molecular dynamics study of the effect of quantum characteristics of hydrogen on its flow characteristics

It is necessary to use the method which consider the uncertainty of position of hydrogen atoms to reproduce the flow characteristics of liquid hydrogen accurately by molecular dynamics method. In this study we treat the quantum characteristics of hydrogen by using path integral centroid molecular dynamics method and analyze the mechanism by which the quantum characteristics of hydrogen affects on the macroscopic flow phenomena of liquid hydrogen.

Construction of proton hopping model to analyze the transport phenomena of proton

In water a proton (H+) exists as an oxonium ion (H2O) by connecting with water molecule (H2O). The diffusivity of oxonium ion is 4-5 times larger than that of water molecule by the mechanism which uses a kind of chemical reaction called "proton hopping". In this study we investigate the characteristics of "proton hopping" by various quantum calculations and make a model to treat proton hopping in the framework of classical molecular dynamics.

Study of dissociation phenomena of molecules on catalyst surface

Dissociation of molecules on a catalyst surface occurs by filling anti-bonding orbitals of molecules with free electrons on metal surface. It is necessary to consider the state of electrons on metal surface to reproduce the phenomenon by molecular dynamics method. In this study we construct an interaction potential which can treat the state of electrons and analyze the dissociation of molecules. Moreover, from the results, we construct the dissociation model of molecules which can be applied to simulations of larger system.

Quantum Nanoscale Flow Systems Laboratory