• Title/Summary/Keyword: Half Wave Length

Search Result 74, Processing Time 0.022 seconds

CAVITY OF CREATION FOR COLD FUSION AND GENERATION OF HEAT

  • Oh, Hung-Kuk
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
    • /
    • 1996.10b
    • /
    • pp.3-12
    • /
    • 1996
  • Cold fusion technologies now are being developed very successfully. The $\pi$-far infrared rays are generated from three dimensional crystallizing $\pi$-bondings of oxygen atoms in water molecules. The growing cavity in water molecules make near resonance state and a vortex of infrared rays and attracts $\pi$-far infrared rays in the water. The cavity surrounded by a lot of $\pi$-far infrared rays has a very strong gravitational field. The $\pi$-far infrared rays are contracted into $\pi$-far infrared rays of half wave length and of one wave length. The $\pi$-far infrared rays of half wave length generate heat while $\pi$-far infrared rays of one wave length are contracted into $\pi$-gamma rays of one wave length. The contracted $\pi$-gamma rays of one wave length make nucleons and mesons, which is the creation and transmutation of matter by covalent bondings and three-dimensional crystallizing $\pi$-bondings into implosion bonding. Patterson power cell generates a very strong gravitational cavity because the electrolysized oxygen atoms make $\pi$-far infrared rays than in plain water.

  • PDF

Acoustic-Damping Characteristics of Half-Wave Resonator in a Combustion Chamber of Liquid Rocket Engine (로켓엔진 연소기에서 반파장 공명기의 음향감쇠에 관한 수치적 연구)

  • Sohn Chae-Hoon;Park I-Sun
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.9 no.4
    • /
    • pp.9-15
    • /
    • 2005
  • A linear acoustic analysis is performed to explore the characteristics of acoustic damping by a gas-liquid scheme coaxial injector in a liquid rocket engine. The injector can play a role of acoustic resonator. Acoustic-damping characteristics of half-wave resonator are compared with those of quarter-wave resonator. Various effects of the boundary absorption coefficient, injector length and sound speed in combustion chamber and resonator are investigated. As a result, short tuning length of resonator and low sound speed of the medium have a favorable effect on acoustic damping. As the boundary absorption coefficient decreases, the tuning range of the resonator length becomes narrower.

An Experimental Study on Effect of Half-Wave Resonator Position on Acoustic Damping in a Combustion Chamber (연소실내 공명기 장착 위치에 따른 음향갑쇠 효과에 관한 실험적 연구)

  • Sohn, Chae-Hoon;Kim, Chul-Hee
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.12 no.2
    • /
    • pp.1-7
    • /
    • 2008
  • Effect of radial position of half-wave resonator is investigated experimentally for acoustic damping in a combustion chamber by adopting acoustic cold test. Acoustic damping is quantified by damping factor. When resonator with optimal tuning length is installed, damping is enhanced as its radial location is away from the center of the faceplate. And, spatial profile of damping factor is similar to that of the amplitude of the acoustic mode to be damped. As the location is close to the center, acoustic damping is mitigated and independent of the resonator length. On the other hand, the resonator with non-optimal length dose not show any effects of its radial position. Acoustic-damping capacity can be evaluated as functions of resonator length and position.

A Horn of Half-wave Design and Manufacture for Ultrasonic Metal Welding (초음파 금속 용착을 위한 반파장 혼의 설계 및 제작)

  • Kim, Eun-Mi;Jang, Ho-Su;Park, Dong-Sam
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.19 no.6
    • /
    • pp.790-796
    • /
    • 2010
  • This paper designed the horn of half-wave needed for Ultrasonic meta) welding. The horn has to be designed and manufactured accurately, because measurements such as the shape, length, mass and etc. have effects on the resonant frequency and the vibration mode. Designed horn of half-wave has the feature of 40,000Hz of nature frequency, and maximizes vibration range in the Tip by resonance in the frequency of ultrasonic wave machine. In this study, we calculated and analyzed the natural frequency to find the optimal design of the horn that amplified the amplitude about double by the modal analysis and harmonic analysis using ANSYS. And we did FFT analysis of the manufactured horn.

The Energy Absorption Characteristics of Thin-walled Rectangular Tubes (박판 사각튜브의 에너지 흡수 특성)

  • 김천욱;한병기;원종진;임채홍
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.4 no.3
    • /
    • pp.83-91
    • /
    • 1996
  • This paper investigates the energy absorption characteristics of thin-walled rectangular tubes. In the compact mode, the crushing process of a thin-walled tube is analyzed into 3 parts by the ratio of outward to inward fold length. The mean crush load and the half-wave folding length are determined by using minimum energy principle. The effective crush distance can be determined when half-wave folding length is known, and the number of folds is derived when crush distance is given. Thus when the crush distance is given, energy absorption capacity can be estimated with mean crush load and number of folds. And the theoretical value is proven experimentally.

  • PDF

Numerical investigation of detonation combustion wave propagation in pulse detonation combustor with nozzle

  • Debnath, Pinku;Pandey, K.M.
    • Advances in aircraft and spacecraft science
    • /
    • v.7 no.3
    • /
    • pp.187-202
    • /
    • 2020
  • The exhaust nozzle serves back pressure of Pulse detonation combustor, so combustion chamber gets sufficient pressure for propulsion. In this context recent researches are focused on influence of nozzle effect on single cycle detonation wave propagation and propulsion performance of PDE. The effects of various nozzles like convergent-divergent nozzle, convergent nozzle, divergent nozzle and without nozzle at exit section of detonation tubes were computationally investigated to seek the desired propulsion performance. Further the effect of divergent nozzle length and half angle on detonation wave structure was analyzed. The simulations have been done using Ansys 14 Fluent platform. The LES turbulence model was used to simulate the combustion wave reacting flows in combustor with standard wall function. From these numerical simulations among four acquaint nozzles the highest thrust augmentation could be attained in divergent nozzle geometry and detonation wave propagation velocity eventually reaches to 1830 m/s, which is near about C-J velocity. Smaller the divergent nozzle half angle has a significant effect on faster detonation wave propagation.

Numerical Analysis of Wave Deformation with Sea Bottom Variation(II) (해저지형 변화에 따른 파랑의 수치해석(II))

  • 김성덕;이성대
    • Water for future
    • /
    • v.20 no.1
    • /
    • pp.49-54
    • /
    • 1987
  • A numerical analysis of the characteristics of wave reflection over rippled beds (sand bars) was carried out By Boundary Element Method(B.E.M) using linear elements. It is assumed that the incident wave is normal and oblique to the rippled beds and the wave may be and the escribed by two-dimensional linear theory. The accuracy of the computational scheme is investigated by comparing the laboratory data, the analytic measured results of the other researchers. The B.E.M results for the normal incident wave is held for the mechanism of the resonant Bragg reflection at the point where the wave length of the bottom undulation is one half the wave length of the surface wave.

  • PDF

CFD Application for Prediction of Ship Added Resistance in Waves

  • Kim, Byung-Soo;Kim, Yonghwan
    • Journal of Advanced Research in Ocean Engineering
    • /
    • v.4 no.3
    • /
    • pp.135-145
    • /
    • 2018
  • This paper deals with the added resistance of a ship in waves using computational fluid dynamics (CFD). The ship added resistance is one of the key considerations in the design of energy-efficient ship. In this study, the added resistance of a LNG carrier in head waves is computed using a CFD code to consider the nonlinearity and the viscous effects. The unsteady Reynolds Averaged Navier-Stokes equation (RANS) is numerically solved and the volume of fluid (VOF) approach is used to simulate the free surface flows. The length of incident wave varies from half the ship length to twice the ship length. To investigate the nonlinearity effect, both the linear wave condition and the nonlinear wave condition are considered. The heave and pitch motions are calculated along with the added resistance, and the wave contours are obtained. Grid convergence test is conducted thoroughly to achieve the converged motion and resistance values. The calculated results are compared and validated with experimental data.

Polarization Diversity Antenna for Receiving Traffic Information Contents in WiBro System (교통정보 컨텐츠 수신을 위한 WiBro용 편파 다이버시티 안테나)

  • Jung, Byung-Woon
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.7 no.2
    • /
    • pp.56-61
    • /
    • 2008
  • Diversity antenna system against multi-fading environment is strongly required for WiBro service of vehicle. In general, high isolation performance between antennas leads to good diversity gain. In this paper, a polarization diversity antenna is presented, which has orthogonal polarizations and good isolation characteristic. In addition, by simulation and measurement, it is certified that HWLLA (Half Wave Length Loaded Antenna) improves polarization purity on common ground. In isolation between two antennas, HWLLA can provide better isolation over 12dB than conventional PIFA (Planar Inverted F Antenna).

  • PDF

Numerical Study of Acoustic Coupling between Combustion Chamber and Resonators in Liquid Rocket Engine (로켓엔진 연소기와 공명기간의 선형 음향 coupling에 관한 수치적 연구)

  • Park I-Sun;Sohn Chae-Hoon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2005.11a
    • /
    • pp.407-410
    • /
    • 2005
  • Acoustic coupling between combustion chamber and gas-liquid scheme injectors are studied numerically in liquid rocket engine adopting linear acoustic analysis. The injectors can play a role as half-wave resonators. The combustion chamber with numerous injectors shows peculiar acoustic coupling with the injectors. As the injector length approaches a half wavelength or the original tuning length, new injector-coupled acoustic modes show up in the chamber and thereby, the acoustic-damping effect of the tuned injectors is appreciably degraded.

  • PDF