• Title/Summary/Keyword: 초음속 비대칭 노즐

Search Result 7, Processing Time 0.028 seconds

Design and Experimental Verification of Two Dimensional Asymmetric Supersonic Nozzle (이차원 비대칭형 초음속 노즐 설계와 실험적 검증)

  • Kim, Chae-Hyoung;Sung, Kun-Min;Jeung, In-Seuck;Choi, Byoung-Il;Kouchi, Toshinori;Masuya, Goro
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.37 no.9
    • /
    • pp.899-905
    • /
    • 2009
  • Most supersonic-flow test facility has axisymmetric nozzles or two-dimensional symmetric nozzles. Compared to these nozzles, a two-dimensional asymmetric nozzle has advantages of reducing low cost for various Mach number testing and undesirable flow structure such as shock wave reflection because the nozzle part can be directly connected to the test section part in this type of nozzle. The two-dimensional asymmetric nozzle, which was Mach number 2, was designed for supersonic combustion experiment. And it was verified with the numerical analysis and visualization of Mach wave. This study suggested the practical method for design and verification of supersonic two dimensional asymmetric nozzles.

Design of Supersonic Impulse Turbine Nozzle with Asymmetric Configuration using the Optimal Method (최적화기법을 이용한 초음속 충동형 터빈 노즐의 비대칭 설계)

  • Jeong, Soo-In;Choi, Byoung-Ik;Jeong, Eun-Hwan;Kim, Kui-Soon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.04a
    • /
    • pp.61-65
    • /
    • 2011
  • In this paper, the nozzle design with asymmetric configuration using the optimal method is used in order to improve the under- and over-expansion problem of the flow at the supersonic turbine nozzle. For the design of nozzle contour, 8 design variables are selected and the total-to-static efficiency from the nozzle inlet to the wake outlet is considered as the objective function to be maximized. The Fluent6.3 and the iSIGHT-FD program are used for calculation of nozzle flow and design optimization respectively. RBF(Radial Basis Function) method is chosen for approximate optimization algorithm. It is shown that the static efficiency of improved nozzle design increases 1.35% and loss coefficient decreases 19.85% as compared to baseline design.

  • PDF

Design of Supersonic Wind Tunnel for Analysis of Flow over a Backward Facing Step with Slot Injection (슬롯 분사가 있는 후향계단 유동장 분석을 위한 초음속풍동 설계)

  • Kim, Ick-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.11
    • /
    • pp.363-367
    • /
    • 2016
  • A test section of a supersonic wind tunnel was designed for the analysis of flow characteristics over a backward-facing step with Mach 1.0 slot injection in a supersonic flow of Mach 2.5. The cavity flow of a high-speed vehicle is very complex at supersonic speed, so it is necessary to do experiments using supersonic wind tunnels to verify numerical analysis methods. The previous 2D symmetrical nozzle was replaced with an asymmetrical nozzle. The inviscid nozzle contour was designed using Method of Characteristics (MOC), and the boundary layer thickness correction was reflected by experimental data from the wind tunnel. The results were compared with a CFD analysis. The PID control system was changed to be based on the change of tank pressure. This improved the control efficiency, and the run times of supersonic flow increased by about 1 second. The flow characteristics over a backward facing step with slot injection were visualized by a Schlieren device. This equipment will be used for an experimental study of the film cooling effectiveness over a cavity with various velocities, mass flows, and temperatures.

Excremental Study on Wave Drag in Supersonic Wavy Walls (초음속 파동 벽면에서의 조파저항에 관한 실험적 연구)

  • Kwon, Min-Chan;Semenov, Vasily V.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.11a
    • /
    • pp.758-759
    • /
    • 2010
  • In this study, it was experimentally confirmed that the phenomenon of resonance effect of wave drag in two wavy walls. The channel had saw-tooth type of relief surfaces when supersonic gas flows into this channel. Experiment was carried out on the differential apparatus by conducting the comparative test of two nozzles (round sonic nozzle and two-dimensional nozzle with wavy walls). The two-dimensional nozzle was joined alternately with flat walls which had saw-tooth type of symmetrical and asymmetric reliefs. Two-dimensional nozzle was designed for the M=3 and profiled parabolic contour.

  • PDF

A Study on the Performance of Ramp Tabs Asymmetrically Installed in the Supersonic Nozzle Exit (초음속 노즐 출구에 비대칭적으로 설치한 램프 탭의 성능 연구)

  • Kim, Kyoung-Rean;Ko, Jae-Myoung;Park, Jong-Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.35 no.10
    • /
    • pp.934-939
    • /
    • 2007
  • Thrust vector control(TVC) is the method which generates the side force and moment by controlling the exhausting gas directly from the supersonic nozzle to change the trajectory of a missile quickly. In this paper, performance study on the tapered ramp tabs asymmetrically installed in the supersonic nozzle exhaust for the thurst vector control has been carried out using the supersonic cold flow system. To study the shock wave structure and location of the oblique shock wave produced by the ramp tab, the flow field visualization using the schlieren system is conducted. This paper provides the thrust spoilage, three directional forces and moments and distribution of surface pressure on the region enclosed by the tapered ramp tabs.

Performance Characteristics Analysis of a Three Dimensional Asymmetric Pintle Nozzle Induced by Connection-Tube Angle and Pintle Stroke Position (비대칭 3차원 핀틀 노즐의 연결관 각도와 핀틀 위치에 대한 성능 특성 해석)

  • Lee, KangMin;Hong, JiSeok;Sung, Hong-Gye;Heo, Junyoung;Jin, Jungkun;Ha, DongSung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2017.05a
    • /
    • pp.383-387
    • /
    • 2017
  • A three dimensional numerical analysis has been conducted to analyze the effects of a pipe angle, connecting a combustion chamber and a pintle nozzle, and pintle position on pintle nozzle performance. The compressibility correction of $k-{\omega}$ SST turbulent model was implemented to precisely predict the characteristics of complex flow structures inside a supersonic pintle nozzle. Due to an 3-D asymmetric pintle nozzle configuration, complex helical flow streamlines and large flow separations were observed, which resulting in significant nozzle performance losses. As the angle of connection-tube decreases, the coefficient of performance increases and Since the flow structures are evidently changed to the pintle stroke position, the performance characteristics was analyzed.

  • PDF

Control of the Asymmetric Flow in a Supersonic Nozzle (초음속 노즐에서 발생하는 비대칭 유동의 제어에 관한 연구)

  • Matsuo, Shigeru;Setoguchi, Toshiaki;Hashimoto, Tokitada;Tokuda, Seiya;Nagao, Junji;Kim, Heuy-Dong
    • Journal of the Korean Society of Visualization
    • /
    • v.9 no.2
    • /
    • pp.61-65
    • /
    • 2011
  • Several previous works on rocket nozzle flows have revealed the existence of the transition from FSS to RSS and the occurrence of asymmetric flow associated with the boundary layer separation, which can cause excessive side-loads of the propulsion system. Thus, it is of practical importance to investigate the asymmetric flow behaviors of the propulsion nozzle and to develop its control method. In the present study, the asymmetric flow control method using a cavity system was applied to supersonic nozzle flow. Time-dependent asymmetric flow was experimentally investigated with the rate of change of the nozzle pressure ratio. The results obtained showed that the cavity system installed on nozzle wall would be helpful in fixing the unsteady motions of the boundary layer separation, consequently reducing the possibility of the occurrence of the asymmetric flow.