| Rarefied gas flow has received wide attention due to the booming of micro-nano electromechanical systems and aerospace engineering.The frequency of collision between gas moleculars decreases under rarefied conditions,while the interaction between gas and solid surface plays a leading role.As a key issue of rarefied gas dynamics,gas-solid interface interactions are difficult to study by theoretical methods and experimental methods due to physical complexity,and related research progress is relatively slow.In this paper,the interaction model between diatomic molecular nitrogen and metal platinum surface has been constructed.The molecular dynamics method was used to simulate the collision process of gas molecules on solid surface.The velocity sampling method is used to make the incident gas molecules have macroscopic flow characteristics.The effects of gas and wall parameters and incident conditions on the four accommodation coefficients are studied.It is found that the increase of potential energy coefficient and the increase of mass of gas molecular promote the momentum and energy adaptation of gas and solid interaction.The increase of the temperature of wall and incident gas has a negative effect on gas and solid adaptation,and when the bondlength of molecular is the same as the surface potential energy period,the value of the accommodation coefficient is the smallest.The scattering characteristics of gas molecules on the solid surface at specific incident angles and incident velocities have been studied by molecular beam method.It is found that the greater the incident velocity,the greater the correlation between the scattering angle and the incident angle,and the greater the surface roughness,the less the correlation between the scattering angle and the incident angle.The momentum and energy changes of gas molecules at different incident speeds show a certain difference.High-speed incidents will promote the loss of speed and kinetic energy compared to low-speed incidents,and at the same time,the rotational energy will increase substantially. |
