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NUMERICAL AND EXPERIMENTAL INVESTIGATION OF WAVE DYNAMIC PROCESSES IN HIGH-SPEED TRAIN/TUNNELS

Acta Mechanica Sinica 2002年第3期18卷 209-226页

作者：姜宗林 K.Matsuoka a.sasoh K.Takayama LHD Institute of Mechanics Chinese Academy of Sciences Beijing China 100080 Shock Wave Research Center Institute of Fluid Science Tohoku University 2-1-1 Katahira Aoba-ku Sendai 980-8577 Japan

Numerical and experimental investigation on wave dynamic processes induced by high-speed trains entering railway tunnels are presented. Experiments were conducted by using a 1:250 scaled train-tunnel simulator. Numerical simulations were carried out by solving the axisymmetric Euler equations with the dispersion-controlled scheme implemented with moving boundary conditions. Pressure histories at various positions inside the train-tunnel simulator at different distance measured from the entrance of the simulator are recorded both numerically and experimentally, and then compared with each other for two train speeds. After the validation of nonlinear wave phenomena, detailed numerical simulations were then conducted to account for the generation of compression waves near the entrance, the propagation of these waves along the train tunnel, and their gradual development into a weak shock wave. Four wave dynamic processes observed are interpreted by combining numerical results with experiments. They are: high-speed trains moving over a free terrain before entering railway tunnels; the abrupt-entering of high-speed trains into railway tunnels; the abrupt-entering of the tail of high-speed trains into railway tunnels; and the interaction of compression and expansion waves ahead of high-speed trains. The effects of train-tunnel configuration, such as the train length and the train-tunnel blockage ratio, on these wave processes have been investigated as well.

关键词： high-speed train tennel sonic boom numerical simulation experiments

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Application of laser energy deposition to improve performance for high speed intakes

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Propulsion and Power Research 2020年第1期9卷 15-25页

作者： A.Russell M.Myokan H.Bottini a.sasoh H.Zare-Behtash K.Kontis James Watt School of Engineering University of GlasgowG128QQUK Department of Aerospace Engineering Nagoya University464-8603Japan

Research interest has been growing in recent years in supersonic transport,particularly supersonic propulsion systems.A key component of a commonly studied propulsion system,ramjets,is the air *** supersonic propulsion systems a major factor in the overall efficiency is the intake pressure *** refers to the ratio of the average total pressure after the intake to that of the *** phenomenon that can have a large effect on this performance index is flow separation at the *** aim of this work is to examine how pulsed laser energy deposition can be used to improve pressure recovery performance by reducing flow separation at the *** research examines the effects of pulsed laser energy deposition upstream of an intake with an axisymmetric centrebody in a Mach 1.92 indraft wind *** frequency was varied between 1 and 60 kHz with an energy per pulse of 5.6 *** photography was used to examine the fundamental fluid dynamics while total and static pressure downstream of the intake diffuser were measured to examine the resulting effect on the *** imaging shows that the interaction between the laser generated thermal bubble and the leading edge shock produced by the centrebody results in a significant reduction in separation along the intake *** of the schlieren results and the pressure results in tandem illustrate that the average separation location along the length of the centrebody directly correlates to the pressure recovery observed in the *** the optimal laser frequency,found for this Mach number to be 10 kHz,the pressure recovery is found to increase by up to 4.7%.When the laser power added to the system is considered,this results in an overall increase in propulsive power of 2.47%.

关键词： Laser energy deposition Supersonic Flow dynamics Intakes Flow separation

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In-Tube Rocket Propulsion Using Repetitive Laser Pulses

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Journal of Thermal Science 2011年第3期20卷 201-204页

作者： Akihiro sasoh Department of Aerospace Engineering Nagoya UniversityFuro-choChikusa-kuNagoya 464-8603Japan

In 'in-tube propulsion,' that is the combination of conventional rocket propulsion and ballistic range operation,propulsion performance can be enhanced with increases in thrust due to spatial confinement and in payload capa-bility because propellant can be placed off board a *** paper describes proofed concepts of in-tube propulsion by using repetitive laser pulses.

关键词： Propulsion Laser Thrust Blast wave Ablation

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彩色多普勒图像检测非环扎巩膜扣带术对球后血流动力学的影响

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美国医学会眼科杂志（中文版） 2006年第3期18卷 135-138页

作者： Yoshikazu Ito Mikio sasoh Masashi Ido Shunsuke Osawa Yoshikatsu Wakitani Yukitaka Uji 董白霞（译）马景学（校） Department of Ophthalmology Mie University School of Medicine Tsu Mie Japan. 不详

目的：采用彩色超声多普勒成像研究非环扎的节段性巩膜扣带术对球后血流动力学的影响。方法：对单侧孔源性视网膜脱离而行巩膜扣带术的65例65只限。我们采用彩色超声多普勒成像技术。分别于术前、术后2周、12周、24周时对眼动脉、视网... 详细信息

目的：采用彩色超声多普勒成像研究非环扎的节段性巩膜扣带术对球后血流动力学的影响。方法：对单侧孔源性视网膜脱离而行巩膜扣带术的65例65只限。我们采用彩色超声多普勒成像技术。分别于术前、术后2周、12周、24周时对眼动脉、视网膜中央动脉和睫状后短动脉的血流速度进行测量。应用彩色超声多普勒测量收缩期峰值血流速度（PSV）和舒张末期血流速度（EDV）（以厘米／秒计）。结果：随访过程中眼动脉的PSV和EDV无显著变化。术后2周时视网膜中央动脉的PSV和EDV短暂性地降低，但是在术后12周时恢复到术前水平。两侧睫状后短动脉的PSV和EDV在术后持续降低。到术后24周时其血流速度降低的程度有统计学意义（扣带侧PSVP=0．001；EDVP=0．002；非扣带侧PSVP〈0．001；EDVP=0．004）。扣带侧睫状后短动脉的PSV和EDV降低与患者的年龄呈正相关（PSVR=0．40。P=0．001；EDVR=0．32P=0．008）。结论：即使未采取环扎术，巩膜扣带术仍可以引起脉络膜血液循环的亚临床紊乱。年龄是其危险因素。

关键词：球后血流动力学巩膜扣带术环扎术彩色多普勒图像检测舒张末期血流速度彩色超声多普勒视网膜中央动脉

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使用彩色多普勒成像检测无环扎的巩膜扣带术对球后血流动力学的影响

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世界核心医学期刊文摘（眼科学分册） 2005年第12期1卷 34-34页

作者： Ito Y sasoh M Ido M 王大江 Department of Ophthalmology Mie University School of Medicine 2- 174 Edobashi TsuMie 514- 8507 Japan.Dr

Objective: To study the effects of segmental scleral bucklingwithout encircling procedures on retrobulbar hemodynamic conditions using color Doppler imaging. Methods: In 65 consecutive eyes of 65 patients with unilateral rhegmatogenous retinal detachment repaired by scleral buckling, we prospectively measured the blood flow velocities in the ophthalmic artery, central retinal artery, and short posterior ciliary artery using color Doppler imaging before and 2, 12, and 24 weeks after surgery. Peak systolic velocity (PSV) and end diastolic velocity (EDV) (calculated in centimeters per second) were measured using color Doppler imaging. Results: The PSV and EDV in the ophthalmic artery were not changed significantly during follow-up. The PSV and EDV in the central retinal artery were reduced temporarily at 2 weeks after surgery, but at 12 weeks after surgery had returned to presurgery levels. The PSV and EDV in the short posterior ciliary artery on both sides continued to decrease postoperatively, and the reductions became statistically significant by 24weeks after surgery (buckled side: P=.001 for PSV and P=.002 for EDV; unbuckled side: P< .001 for PSV and P=.004 for EDV). The decreases of PSV and EDV in the short posterior ciliary artery on the buckled side were positively correlated with the subject’s age (R=0.40, P=.001 for PSV; and R=0.32, P=.008 for EDV). Conclusions: Scleral buckling procedures can cause subclinical disturbance of the choroidal circulation, even if encircling procedures are avoided. Aging is one of the risk factors for the disturbance.

关键词：巩膜扣带术彩色多普勒成像血流动力学球后脉络膜循环障碍视网膜中央动脉眼动脉血液流速亚临床最大速度

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