Considering an application of oscillating heat pipes (OHPs) for thermal management in space satellites, heat transport characteristics of OHP with ammonia as a working fluid in the low temperature region are investigated experimentally. In this research, the maps of both the maximum heat transport rate and the maximum effective thermal conductivity as heat transfer performances of OHP under constant heat flux condition are widely obtained. The heat transfer performances of OHP filled ammonia 57 wt% under isothermal heating condition are investigated. Under both constant heat flux and isothermal heating conditions, OHPs work according to the almost same heat transport mechanism. In the case of isothermal heating condition, higher pressure difference is required to activate OHPs than constant heat flux condition.
