Focusing Compression due to Steady Supermulti-Jets Colliding for Aerospace Engine

Around 2010, we have proposed a new compressive combustion principle based on the supermulti-jets colliding with a pulse. It has possibilities to achieve high thermal efficiency, improve durability, and reduce noises. Around 2012, we developed the prototype engine having 14 jets colliding. However, more highly compression is necessary to stabilize combustion and acquire large thrust. Therefore, last year, we created the second prototype engine having jets more than the first one, i.e., 24 supermulti-jets. The second engine is made with a metal 3D printer because the geometrical distribution of 24 jet passages (nozzles) is overly complex. To check whether there are problems such as crack due to the 3D printer, we performed steady flow experiments at high pressure over 1.0 MPa at intake and around colliding point at the JAXA Kakuda Space Center, although fuel was not injected, i.e., without combustion. This high pressure over 1.0 MPa at JAXA Kakuda Space Center corresponds to combustor pressure in combustion experiments conducted in Waseda University at the intake pressure condition of 0.3 MPa. As a result, the new second prototype engine withstood the high pressure over 1.0 MPa without cracks in the combustor and also from the standpoint of appearance. Then, we certainly confirmed the compression effect due to supermulti-jets under steady flow conditions. Furthermore, the pressure at the center of the combustor obtained by the experiment is compared with the computation result obtained by our original numerical methods and codes. These results will lead to shock tube experiments and combustion tests very soon. Then, we will also check whether auto-ignition without a compulsory ignition system is possible.