TY - JOUR
T1 - Unsteady three-dimensional computations and experiments of compression flow formed by collision of supermulti-jets
AU - Tsuru, Kohta
AU - Konagaya, Remi
AU - Kawaguchi, Sota
AU - Naitoh, Ken
N1 - Funding Information:
This article is part of the outcome of research performed under a JSPS Grant for research projects (25630072). The authors sincerely thank the Osaka University Computer Center for lending a supercomputer for performing the computations.
Publisher Copyright:
© 2018 The Japan Society of Mechanical Engineers.
PY - 2018
Y1 - 2018
N2 - The single-point compression principle, based on the collision of pulsed supermulti-jets, which is proposed in our previous reports, has the potential of obtaining both a high compression ratio and relatively low combustion noise, leading to a lower exhaust gas temperature, i.e., high thermal efficiency for the next generation of engines. The supermulti-jets also enclose high-temperature combustion gas around the chamber center, which means less heat loss to the chamber wall, i.e., higher thermal efficiency due to the air-insulation effect. Here, experimental and computational visualizations around the compression point should be examined in order to confirm the occurrence of single-point compression. Thus, in the present paper, we present experimental Schlieren photographs of flows formed by the collision of supermulti-jets without combustion and the results of unsteady three-dimensional computations conducted with the compressible Navier-Stokes equations, while the Cubic Interpolated pseudo-Particle (CIP) and Combined Unified Procedure (CUP) method is employed as numerical algorithm. Comparison of the experimental and computational results show fairly good agreement in time and space. Schlieren photographs and computational visualizations obtained for various conditions of four-, eight-, and sixteen- nozzles of jets are axial symmetrical, which will indicate the single-point compression based on the collision of supermulti-jets. Computations for asymmetrical distribution of seven nozzles also bring results showing nearly symmetric flow.
AB - The single-point compression principle, based on the collision of pulsed supermulti-jets, which is proposed in our previous reports, has the potential of obtaining both a high compression ratio and relatively low combustion noise, leading to a lower exhaust gas temperature, i.e., high thermal efficiency for the next generation of engines. The supermulti-jets also enclose high-temperature combustion gas around the chamber center, which means less heat loss to the chamber wall, i.e., higher thermal efficiency due to the air-insulation effect. Here, experimental and computational visualizations around the compression point should be examined in order to confirm the occurrence of single-point compression. Thus, in the present paper, we present experimental Schlieren photographs of flows formed by the collision of supermulti-jets without combustion and the results of unsteady three-dimensional computations conducted with the compressible Navier-Stokes equations, while the Cubic Interpolated pseudo-Particle (CIP) and Combined Unified Procedure (CUP) method is employed as numerical algorithm. Comparison of the experimental and computational results show fairly good agreement in time and space. Schlieren photographs and computational visualizations obtained for various conditions of four-, eight-, and sixteen- nozzles of jets are axial symmetrical, which will indicate the single-point compression based on the collision of supermulti-jets. Computations for asymmetrical distribution of seven nozzles also bring results showing nearly symmetric flow.
KW - Computation
KW - Engine
KW - Point compression
KW - Schlieren photography
KW - Shock tube
KW - Supermulti-jets
UR - http://www.scopus.com/inward/record.url?scp=85046890855&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85046890855&partnerID=8YFLogxK
U2 - 10.1299/jtst.2018jtst0010
DO - 10.1299/jtst.2018jtst0010
M3 - Article
AN - SCOPUS:85046890855
VL - 13
JO - Journal of Thermal Science and Technology
JF - Journal of Thermal Science and Technology
SN - 1880-5566
IS - 1
M1 - JTST0010
ER -