A two-phase computational fluid dynamics (CFD) simulation of seven parallel evaporating branches in a separate heat pipe with two different heat loads was conducted and the flow distribution characteristics was assessed in the study. In the CFD calculation

the evaporation source term is added to the continuity equation while the surface tension source term is added to the momentum equation. The simulation results show that (1) at a lower heat load with a pool temperature of 60 ℃

the mass flow rate is higher in the branches of the two sides and smaller in the middle

and branch 1 has the highest mass flow rate of 0.025 kg/s while branch 4 has the lowest mass flow rateof 0.016 kg/s; (2) at a higher heat load with the pool temperature at 80 ℃

the mass flow rate of each branch is gradually reduced along the flow direction

where branch 1 has the highest mass flow rateof 0.025 kg/s while branch 7 has the lowest mass flow rateof 0.017 kg/s. The simulation results are compared to the experimental results regarding parallel branches of separation heat pipes

and the comparison shows that the effect of the heat load on the flow distributionin the simulation results is consistent with theexperimental ones.