Rocket propulsion for extraterrestrial space launches
Will we ever go to Mars in the future and how do we come back? During recent years there is an ongoing research and development of reusable rocket engines for space launches, much driven by private entrepreneurs with space exploration for human advances on the agenda. In this docent seminar Jens Fridh will tell you more.
Tid: To 2019-08-22 kl 13.00 - 13.45
Föreläsare: Jens Fridh
Plats: Brinellvägen 68, EGI, EKV LEARNING THEATRE
One promising fuel studied is methane and a propulsion system using hydrocarbons, liquid or hybrid, is a challenge for today’s rocket and space propulsion systems. As a consequence of the good performance in specific thrust in combination with operating benefits such as low toxicity, availability, storage stability and low production cost liquid biogas/natural gas (LNG) with a high content of methane is one of the most interesting future propellants for rocket engines with liquid fuel. It is of strategic importance that the industry and academia develop necessary knowledge of the heat transfer characteristics and material influence at relevant operating conditions.
Here the focus is on methane in gas phase as a coolant for the rocket nozzle walls. Before combustion the fuel is lead through cooling channels in the rocket nozzle in order to cool it to withstand the high heat load from the rocket flame. Fuels with a high content of methane can contain impurities such as sulfur that leaves deposits on the metal surface that in turn increases the pressure loss and decreases the heat transfer, which ultimately can lead to failure of the rocket nozzle. Furthermore, methane undergoes thermal decomposition at high temperatures that leads to coking of cooling channels, which is affected by the amount of nickel in the surrounding material. A combination of conjugate heat transfer calculations and experiments in a dedicated test rig at Energy Technology, Royal Institute of Technology (KTH), Sweden are performed in order to characterize methane’s impact on the nozzle cooling channels in terms of heat transfer, coking and pressure loss.