本實驗探討二維超音速噴流與空穴管正向交互作用下之流場行為，實驗設計上選擇管長，噴嘴至空穴管口的間距，噴流全壓比，空穴管漸縮比作為研究的參數來觀測管內壓力震盪的模式與底端溫度上升的關係。

　傳統軸對稱音速噴嘴與空穴管交互流場現象主要有吞吐模式與尖聲模式兩種，其模式主要取決於噴流全壓比大小與噴嘴至空穴管口的間距的長短，而在尖聲模式下穴管底有溫度迅速提昇的情形。本實驗發現在不足膨脹的二維超音速噴流作用下，由不同全壓比、空穴管口至超音速噴嘴出口的間距、不同空穴管長、不同空穴管漸縮比的各種測試發現，並沒有單純的吞吐模式或尖聲模式存在，經常是吞吐模式伴隨著尖聲模式，或尖聲模式伴隨著吞吐模式發生，由二維流場觀察所拍攝圖片和測量所得空穴管內的壓力波動頻譜分析結果，比較軸對稱音速噴嘴流場中歸納為吞吐模式的相同區域(空穴管放置的距離大於自由噴流結構位置)，本實驗顯示二維的噴流結構在空穴管的影響下無法完整的建立不足膨脹噴流的震波與膨脹波結構，而且有震波在穴管前震盪。

　研究結果發現其流場結構存在的模式由何者主導，主要跟總壓和穴管與噴嘴的距離有直接的關係，而漸縮比與管長，在某些吹試條件下也有相當顯著的影響。由於同時存在的吞吐模式流場結構之中其空穴管中有氣流的進出，使能量無法累積在管底，因此導致在穴管底端溫度無法有顯著的提昇。

　The objective of this research is to discuss the behavior of the interaction of two-dimensional supersonic jet to cavity flow. In the experiment the testing parameters are length of the tube, distance between supersonic nozzle outlet and cavity inlet, and the tapered ratio of the cavity, the pressure oscillation inside the cavity tube and temperature rising at the end of the cavity are being examined.

　In the former research, the interaction of axial symmetric sonic jet and cavity tube was observed in to two modes, which were regurgitant mode and screech mode. The conditions for each mode are total pressure of the jet and the location between the jet and the cavity. For axial symmetric sonic jet, there exists a large temperature rising at the end of the cavity for screech mode. However, it has been observed there are no pure regurgitant mode and screech mode with two-dimensional under expansion supersonic jet under different total pressure of jet, distance between nozzle outlet and cavity inlet, and length, and taper ratio of the cavity. The spectrum of the dynamics pressure measured shows that it is a mixing of regurgitant mode and screech mode in the flow field. From photos of the flow field observation and spectrum analysis of pressure oscillation inside the cavity, it has been observed that the simple structure of the regurgitant mode can not be built up with large enough jet to cavity distance, ahd there exists shock wave oscillates in front of the cavity.

　It has been observed that which mode takes the major part in the flow field depend on the total pressure of the jet and distance between the cavity and supersonic jet nozzle. However, the cavity length and tapered ratio can also show remarkable influence in some case. Since there always exists a mixed regurgitant mode in the flow structure, thus energy can not be accumulated at the cavity end thus the temperature can not rise dramatically.

[1] J. Hartmann, “On the Production of Acoustic Wave by Mean of an Air-Jet of a Velocity Exceeding That Sound,” Philosophical Magazine, Vol. 11, pp.926-948, 1931.

[2] L. E. Savory, “Experiments with the Hartmann Acoustic Generator,” Engineering, Vol.170, pp.99-100, pp.136-138, 1950.

[3] H. Sprenger, “Zurich Über Thermisch Effekkte in Resonanzohren,” Mitteilungen aus dem Institut fur Aerodynamik an der E. T. H., Vol. 21, pp.18-31, 1954.

[4] T. J. B. Smith, A. Powell, “Experiments concerning the Hartmann Whistle,” Rept.64-62, Department of Engineering, University of California, 1964.

[5] L. D. Rozenberg, “Sources of High-Intensity Ultrasound,” Moscow Science Press, 1967.

[6] E. Brocher, C. Maressca and M. H. Bournay, “Fluid Dynamics of the Resonance Tube” Journal of Fluid Mechanics, Vol.43, pp.369-384, 1970.

[7] Maddox, A. R. and Binder, R. C., “A new dimension in Schlieren technique: Flow field analysis using color,” AIAA paper 70-223, 1970.

[8] J. H. Wu, T. Ostrowski, R. A. Neemeh and P. H. W. Lee, “Experimental Investigation of a Cylindrical Resonantor,” American Institute of Aeronautics and Astronautics Journal, Vol.12, pp.1076-1078, 1974.

[9] M. Kawahashi and M. Suzuki, “Studies of Resonance Tube with a Secondary Resonantor,” Bulletin of the Japan Society of Mechanical Engineers, Vol.17, pp.595-602, 1974.

[10] J. Iwamoto, K. MO, I. Arga and I. Watanabe, “On Thermal Effects of Hartmann-Sprenger Tubes with Various Internal Geometries,” Oscillatory Flow in Ducts, Euromech 73, Aix-en-Preovence, 1976.

[11] J. H. Wu, T. Ostrowski and R. A. Neemeh, “Acoustic Performance of a Cylindricall Disk-Type Resonantor,” Journal of Sound and Vibration, Vol.60, pp.151-156, 1978.

[12] M. Kawahasha and M. Suzuki, “Generative Mechanism of Air Column Oscillation in a Hartmann-Sprenger Tube Excited by and Air-jet Issuing from a Convergent Nozzle,” Zeitschriften fur angewandte Mathematik und Physik, Vol.30, pp.797-810, 1979.

[13] M. Kawahasha and M. Suzuki, “Thermal Effect in a Hartmann-Sprenger Tube,” Bulletin of the Japan Society of Mechanical Engineers, Vol.22, pp.685-692, 1979.

[15] V. Sarohia and L. H. Back, “Experimental Investigation of Flow and Heating in a Resonance Tube,” Journal of Fluid Mechanics, Vol.94, pp.649-672, 1979.

[14] W. M. Jungowski and G. B. Sobieraj, “Hartmann-Sprenger Generator as a Sound Source of a Discrete Frequency,” Bulletin of the Static University of Mining and Metallurgy, Vol.728, pp.137-145, 1979.

[16] E. Brocher and G. Pinna, “Aeroacoustical Phennomena in a Horn excited by a Hartmann-Sprenger Tube,” Acoustica, Vol.45, pp.180-189, 1980.

[17] M. Kawahashi and M. Suzuki, “Temperature Separation Produced by a Hartmann-Sprenger Tube Coupling a Secondary Resonantor,” Journal of Heat and Mass Transfer, Vol.24, pp.1951-1958, 1981.

[18] M. Kawahashi, R. Bobone and E. Brocher, “Oscillation Modes in a Single-Step Hartmannn-Sprenger Tube,” Journal of the Acoustical Society of America, Vol.75, pp.780-784, 1984.

[19] R. A. Neemeh and P. P. Ostrowski, “Thermal Performance of Logarithmicspiral Resonance Tube,” American Institute of Aeronautics and Astronautics Journal, Vol.22, pp.1823-1825, 1984.

[20] W. M. Jungowski and G. E. A. Meier “Planar jets impinging on various obstacles and some modes oscillation,” Mitteilungen der Mas-Planck-Institut for Stromungsforschung, Vol.78, pp.347-353, 1984.

[21] Settles, G. S., “Modern Developments in flow visualization,” AIAA J., vol. 24, No. 8, pp. 1313-1323. , 1986.

[22] W. M. Jungowski and G. Grabitz, “Selfsustained Oscillation of a Jet Impinging upon a Helmholt-Resonanto,r” Journal of Fluid Mechanics, Vol.1799, pp77-103, 1987.

[23] G. B. Sobeiraj and A. P. Szumowski, “Experimental Investigations of an Underexpanded Jet from a Convergent Nozzle Impinging on Cavity,” Journal of Sound and Vibration, Vol.149, No.3, pp.369-375, 1991.

[24] Goldstein, R. J., “Fluid Mechanics Measurements”, Second edition, Taylor & Francis publishers, University of Minnesota, pp. 451-474, 1996.

[25] 王昌楠, “Experimental Study on the Shock Oscillating in an Underexpanded Jet to Cavity Interaction Flow,” 國立成功大學航空太空工程研究所碩士論文, 1997.

[26] 施純榮, “Effect of Constant Height Throat Section on a Two-Dimensional Nozzle,”國立成功大學航空太空工程研究所碩士論文, 2000.