Background: Vortex diode was a critical equipment of the passive residual heat removal system. The diodicity will affect the residual heat removal capability during accident conditions and heat losses during normal operations of the fluoride-salt-cooled high-temperature reactor (FHR). And difficulty and high cost of coolant FLiBe salt experiments are stirred up due to its strong corrosion and high melting point. Purpose: The aim is to find out whether alternative fluids that are safer and experimental friendly

such as H2O

#22 turbine oil and HTS-1 (NaNO3-NaNO2-KNO3

7%-40%-53%) could be used in the experiment to study the diodicity of the vortex diode. Methods: A fluid to fluid modeling method based on the similarity principles was adopted. In addition

the feasibility of the modeling was studied using computational fluid dynamics (CFD). Results: The flowing condition of HTS-1 in the vortex diode can have a complete similarity to the FLiBe

and #22 turbine oil and H2O can have a partial similarity to the FLiBe. Conclusion: It is feasible to use HTS-1

H2O and #22 turbine oil instead of FLiBe to study the diodicity of a vortex diode with same structures. Abstract