Based on the p rinciple of molecular dynamics

a sampling met hod in Direct Simulation<br />Monte Carlo (DSMC) met hod for molecular total and t ranslational energy

and t he heat flux vec2<br />tor nearby t he wall boundary is propo sed. An important relationship among t he mean incident en2<br />ergy

reflective energy and t he wall boundary heat flux is obtained by statistically averaging t he<br />energy values of t hose molecules colliding wit h wall . Combining the generating met hod of molec2<br />ular reflective t hermal velocities according to diff use reflection model

an algorit hm named as In2<br />ver se Temperat ure Sampling ( ITS) is developed

which enables to evaluate the molecular reflec2<br />tive characteristic temperature f rom t he molecular incident energy and t he boundary heat flux.<br />The numerical result s show t hat t he molecular reflective temperature is accurately sampled wit h<br />t his algorit hm

t hus the information of heat flux at wall boun