The effects of real gas and turbulence have a great influence on the performance of supercritical carbon dioxide(S-CO_2) dry gas seal. A typical spiral groove dry gas seal calculation model is established

and the flow equation on the end face of supercritical carbon dioxide dry gas seal is solved by CFD software to obtain the flow state of fluid between the seal slots. The influence of real gas and turbulence effects on opening force and leakage are investigated under different rotational speed. The results show that both real gas and turbulence effects make the pressure distribution of the gas film change significantly. The real gas effect improves the opening force and leakage of gas film

and the strengthening effect on the opening force becomes stronger with the increase of the rotational speed

while the effect on the leakage almost does not change with the rotational speed. At low rotational speed

the turbulence effect has a weak effect on the opening force. With the increase of rotational speed

the opening force increases sharply due to the turbulence effect

and the increase increases with the increase of rotational speed.In the high speed S-CO_2 dry gas seal

the combined effect of real gas and turbulence effect makes the opening force of gas film increase significantly

and the turbulence effect is greater than the real gas effect.