• Title/Summary/Keyword: pulse pressure

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A Study of Rupture Pressure for Membrane Type Pulse Separation Device of Dual Pulse Rocket Motor (이중펄스 추진기관의 펄스분리장치 파열압력 분석기법 연구)

  • Kim, Seil
    • Journal of the Korean Society of Propulsion Engineers
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    • v.26 no.1
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    • pp.98-106
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    • 2022
  • To develop reliable dual pulse rocket motor, vacuum ignition performance at high altitude and design stability for rupture pressure of the Pulse Separation Device(PSD) are required. In this study, rupture pressure analysis method for the membrane type PSD of the dual pulse rocket motor was developed. The PSD rupture pressure formulation was derived from strain-pressure relationships. The PSD vacuum rupture test apparatus and the PSD 1 second vacuum ignition test apparatus were developed, which can simulate the high altitude vacuum environment. Rupture pressure of PSD was analyzed by conducting the PSD vacuum rupture test, and design values of PSD were derived. Finally, vacuum ignition performance and rupture pressure of the designed PSD were validated with PSD 1 second vacuum ignition test.

Dynamic Pressure Characteristics of Pulse Gun Device for Combustion Stability Rating of Liquid Rocket Engines (액체 로켓엔진 연소 안정성 평가를 위한 압력 교란 장치 특성 연구)

  • Seo,Seong-Hyeon;Go,Yeong-Seong;Lee,Gwang-Jin;Park,Seong-Jin;Lee,Su-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.7
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    • pp.94-99
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    • 2003
  • For the assessment of combustion stability of a liquid rocket engine, a device called "Pulse Gun" should be developed first, which can induce artificial perturbations that may lead to excitations of pressure oscillations in a combustion chamber. A model chamber has been used for identifying design parameters of a pulse gun that defines its characteristics. Dynamic pressure measurements showed that shock waves generated from pulse guns are axisymmetric around the axis of a pulse gun barrel. Pressure waves perturbed by a pulse gun induce resonant acoustic frequencies of a model chamber. This fact indicates that successful pressure field perturbations of the KSR-III combustion chamber can be performed by a newly developed pulse gun device. A maximum value of dynamic pressure peaks measured at the opposite point against a pulse gun outlet becomes stronger as charge mass of pulse gun powder increases.

Performance Test of Domestic Glass Fabric by varying cleaning conditions in a Pulse-Jet Cleaned Fabric Filter (충격기류 탈진방식 여과포집진장치에서 탈진조건 변화에 따른 국산유리섬유여과포의 성능시험)

  • 박영옥;구철오;임정환;김영성;손재익
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.3
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    • pp.183-190
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    • 1994
  • Performance of domestic glass fabrics was tested in a Pulse- jet cleaned fabric filter under simulated coal combustion. Pulse Pressure were 2.5, 4.0kgf/$\textrm{cm}^2$ and pulse air nozzle diameter were 4.0, 6.0mm Pressure drop and penetration turned out to be low at small pulse air nozzle diameter and low pulse air pressure. Fractional penetration through the dust cake and fabric at face velocity of 1.7m/min was higher than that at face velocity of 1.0m/min. As a consequense, the performance of domestic glass fabrics was better with face velocity of less than 1.0m/min, pulse air pressure of 2.5 kgf/$\textrm{cm}^2$ and pusle air nozzle diameter of 4.0mm.

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Pressure Measurement in Double Inlet Pulse Tube Refrigerator (이중 입구형 맥동관 냉동기에서의 압력 파형 측정)

  • 정제헌;남관우;정상권;정은수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.4
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    • pp.390-396
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    • 2004
  • A double-inlet pulse tube refrigerator was fabricated as a U-shape with $\Phi$19.0 mm${\times}$125 mm regenerator packed by #200 stainless steel mesh and $\Phi$12.7 mm${\times}$125 mm pulse tube. A pressure sensor was installed at the inlet of the regenerator and a differential pressure sensor was installed across the bypass. Amplitude of the pulsating pressure was independent of the opening of the orifice and the bypass valves. Helium flow through the orifice and the bypass was calculated based on the measured pressure. Energy loss through the orifice and the bypass was evaluated with the measured pressure and the calculated helium flow rate. The energy loss, which is equivalent to the refrigeration capacity at the cold end of the ideal pulse tube refrigerator, was mainly generated through the orifice. It was proportional to the opening of the orifice valve, but the real refrigerator displayed the best performance at the optimized opening of the orifice valve. This optimized performance of the tested pulse tube refrigerator can be explained by additional refrigeration losses. As an example, the shuttle heat transfer loss of the pulse tube was calculated from the measured experimental data.

The Effect of Guided Imagery on Blood Pressure and Pulse Rate - In Nursing Students - (지시적 심상요법이 혈압과 맥박에 미치는 효과 - 간호대학생을 대상으로 -)

  • Choi, Eun-Ok;Lee, Dong-Suk
    • Journal of Korean Biological Nursing Science
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    • v.5 no.2
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    • pp.31-39
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    • 2003
  • The purpose of this study was to test the effect of guided imagery on blood pressure and pulse rate. The subjects were thirty-nine nursing students in I university located in Busan, Korea To enhance the effect of treatment, they were trained getting themselves absorbed in guided imagery on three different occasions before the study. Actually in the study, the subjects were given instruction in Mason's guided imagery for 19 minutes and 58 seconds. Blood pressure and pulse rate were measured before and after guided imagery application. The data were analyzed through paired t-test. The Results were as follows : 1) There was a significant decrease in systolic blood pressure after the use of guided imagery. 2) There was no significant decrease in diastolic blood pressure after the use of guided imagery. 3) There was a significant decrease in pulse rate after the use of guided imagery. These results indicate that guided imagery is a helpful technique for decreasing blood pressure and pulse rate, which are increased in stress condition.

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Development of Cardiovascular Simulator with Control of Pulse Pressure for Pulse Wave Study (맥압조절이 가능한 맥파 연구용 심혈관계 시뮬레이터 개발)

  • Lee, Ju-Yeon;Kim, Jeauk U.;Shin, Sang-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.10
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    • pp.204-209
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    • 2014
  • The purpose of this study is to produce a simulator that can control a pulse pressure keeping the pulse wave transfer phenomenon. For this, the elastic tube is combined with a compliance chamber for the vessel part. The simulator is comprised of four parts; a pressure generation part with slider-crank mechanism, a vessel part with resistance controller, water reservoirs and a measurement part. The changes of waveform depending on the location of a chamber is examined to determine the position of a chamber. The effects of a chamber on the pulse pressure and the pulse wave transfer phenomenon were investigated. It showed that the simulator which had the chamber in upstream of tube produces pressure wave, being more similar to the clinical waveform than in downstream of tube. Furthermore, with the chamber, the simulator generates a pulse pressure, being more similar to the normal physiological values than without one. The chamber had little effect on the pulse wave velocity.

Analysis of Blood Pressure Pulse in Female High School Students with Menstrual Disorders (월경장애를 가진 여고생의 맥진분석)

  • Kim, Soo-Hyun;Cho, Hye-Sook;Lee, In-Seon
    • The Journal of Korean Obstetrics and Gynecology
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    • v.26 no.1
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    • pp.82-91
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    • 2013
  • Objectives: The purpose of this study is to find out the patterns of teenage girls who is easy to suffer from Menstrual Disorders. Methods: The data from the 1681 participants were collected using a structured menstrual history questionnaire. Based on the survey responses, we had 97 adolescents with menstrual disorder as the test group and 97 adolescents without menstrual disorder as the control group. The clinical trials subjects were asked to respond to another questionnaire for identifying Blood Pressure Pulse Analyzer tests. We identified significant variables for dysmenorrhea from comparison between the test and control group; a binary response variable from the test group's responses for ever experiencing dysmenorrhea and explanatory variables from Blood Pressure Pulse Analyzer. Results: The reselts of Blood Pressure Pulse Analyzer test showed that the score of Energ_R, EIX_R were lower in dysmenorrhea group than the control group. The reselts of Blood Pressure Pulse Analyzer test showed that the score of Energ_R, EIX_R were lower, and T4_R were higher in hypomenorrhea group than the control group. The reselts of Blood Pressure Pulse Analyzer test showed that the score of Energ_R, EIX_R were lower in Irregular Menstruation group than the control group. Conclusions: Blood Pressure Pulse Analyzer test showed that the score of Energ_R, EIX_R were lower in the test group than the control group.

Development of Pulse Diagnosis Hold-down Pressure Measurement System (맥진 가압 프로파일 측정 시스템 개발)

  • Lee, Jeon;Lee, Yu-Jung;Jeon, Young-Ju;Ryu, Hyun-Hee;Woo, Young-Jae;Kim, Jong-Yeol
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1997-1998
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    • 2008
  • Pulse diagnosis is the one of the most important diagnostic process to traditional medical doctors. Although the pulse diagnosis position, Gwan is apart from Chon or Cheok by 10$\sim$20mm at most, traditional medical doctors applies different indent pressures and even they states different pulse images are felt at Chon, Gwan and Cheok. One the other hand, the education on pulse diagnosis behavior includes tantalizing problem caused by no tool for communication between trainer and trainee. On account of this situation, we tried to develop a system which can measure the hold-down pressure during a pulse diagnosis and compare the hold-down pressure profile of trainer and that of trainee. This system can be divided into three parts - pulse pressure sensing part, signal acquisition part and data storing part. A correction curve was generated by the relation between output voltages and standard weights. Using this system, 3 channel hold-down pressure profile of a oriental medical doctor were recorded three times. In the profile, three period were observed and all period included two process for searching the depth of pulsation and for classifying the pulse feeling into one or more of 28 pulse types. The maximum value of pulse profile was 1.3$kg{\cdot}f$ which was more than reported by previous chinese groups and the mean values of three channel ranged from 240$g{\cdot}f$ to 430$g{\cdot}f$. In frequency domain, each channel has some dominant frequency components - about 10Hz, 35Hz and 75Hz. In further study, we want to collect more profiles from lage number of oriental medicine doctors and hope to develop a measuring system which can measure the hold-down pressure on subject's skin directly.

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The Fundamental Study on Pulse Jet Cleaning of Rectangular Bag-Filter System (사각형 여과 집진기 충격기류 탈진시스템의 기초 연구)

  • Piao, Cheng Xu;Kim, Tae Hyeung;Yang, Jun Ho;Li, Xiao Yu;Ha, Hyun Chul;Jung, Jae Hun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.18 no.2
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    • pp.149-160
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    • 2008
  • Bag-filter system has been widely used in industrial field to remove the particulate matters from the exhaust gas. The cylindrical type of bag-filter has been generally used. But it has many shortcomings. The reattachment of separated particles on the surface of bags could result in high pressure drop of bag-filter system and subsequent decrease of air flow rate since the cylindrical type bag-filter system should have the upward flow pattern. In addition, the supply of very high pressure pulse air jet to remove particulate matters on the surface of filter could result in a frequent rupture of bags. To overcome these shortcomings of the cylindrical type, the rectangular type was developed in the developed countries and imported to Korea. But, there was not many design data available to understand the mechanisms. Thus, the fundamental experiments were conducted in this study to get some ideas about the pulse jet cleaning of rectangular type bag filter system. The experimental factors are as follows; pulse distance, pulse duration, pulse interval, pulse pressure and pulse nozzle type. Experiments followed the factorial design method. With the shorter pulse distance, the distribution of pressure drops was relatively not uniform while the particulate removal efficiency was higher. With the longer duration of pulsing and the more number of pulse nozzle, the removal efficiency was higher and the pressure drop distribution was more uniform.

Multi-Point Radial Artery Pulse Wave Transducer using Pneumatic System (공압 방식에 의한 다지점 요골 맥파 검출 장치)

  • 이종진;정민석;황성하;이종현;이선규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.243-248
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    • 2001
  • A radial artery pulse wave is well known as a good mans to diagnose human body condition in th field of Chinese medical science. Information about constitution as well as organs can be obtained by detecting the artery pulse wave. Recently, the information about the human body constitution may be utilized in accelerating the recovery process of the patient on the basis of comprehensive diagnosis. A radial artery pulse wave is considered as one of promising means in examining the human body constitution. Since the examination has been conducted by the feeling of finger, the diagnosis may occasionally have uncertainty or fatal error. In this paper, a new measuring system is suggested and developed to examine the pattern of a pulse wave correctly. The system is composed of four pressure vessels, pressure sensors and air supplying pumps. One of them is utilized for appropriately pressing the radial artery, three of them for detecting pressure change in several mmHg level. The detected data is shown and discussed.

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