Gas‐dynamic pressure‐wave machine with reduced noise amplitude

1991 ◽  
Vol 90 (5) ◽  
pp. 2877-2878 ◽  
Author(s):  
Andreas Mayer
Keyword(s):  
Pressure Wave ◽  
Dynamic Pressure ◽  
Noise Amplitude ◽  
Gas Dynamic

Calculation of plasma centrifugal spraying parameters of fine granules of heat-resistant nickel alloys

2020 ◽  
pp. 471-474
Author(s):  
M.G. Yagodin ◽  
E.I. Starovoytenko
Keyword(s):  
Powder Metallurgy ◽  
Nickel Alloys ◽  
Dynamic Pressure ◽  
Calculated Data ◽  
Powder Size ◽  
Metal Powders ◽  
Heat Resistant ◽  
Gas Dynamic ◽  
Spraying Parameters ◽  
Wide Range

The equipment for the production of wide range of metal powders purposed for powder metallurgy is described. The possibility for producing of powders by the plasma centrifugal spraying is considered taking into account the gas dynamic pressure. The calculated data on the powder size for different materials are given.

Comparison of Three Types of Common Rail Systems Suited for Diesel Engines From 1 to 5 Megawatt

2006 ◽  
Author(s):  
Marco Ganser ◽  
Ulrich Moser
Keyword(s):  
Diesel Engines ◽  
Pressure Wave ◽  
Dynamic Pressure ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail ◽  
Wave Dynamics ◽  
Rail Systems ◽  
Heavy Duty Diesel ◽  
The Individual

The basic physical law governing the injection in Common Rail Systems is the compressibility of the fuel. The effects of pressure wave dynamics, the layout of the system volume and its geometrical distribution strongly affect the injection events at every injector. In this Paper, three different arrangements of system volumes and their effect upon the performance of the individual injectors are compared using the hydraulics simulation tool AMESim. Two systems are known in the passenger car and the heavy duty diesel engine domains. The third system is new and takes advantage of pressure wave dynamics to tailor the injection event. This system is best suited for Diesel Engines with a power from 1 to 5 MW, as used in locomotives, ships, power generation and heavy earthmoving machinery. It produces a more favorable pattern of the injection pressure and injection rate shape during any injection event by hydraulically interconnecting the individual injector’s accumulators during the injection and taking advantage of pressure wave dynamics. Right after the end of each injection, dynamic pressure pulsations are evened out with a dampening device. A multi-cylinder system provides equal conditions for all injections. Its very simple design and increased performance makes the novel system of very attractive use in the above mentioned fields.

scholarly journals Cavitation onset caused by a dynamic pressure wave in liquid pipelines

2020 ◽  
Vol 68 ◽  
pp. 105225
Author(s):  
Cuiwei Liu ◽  
Xuejie Li ◽  
Anqi Li ◽  
Zhaoxue Cui ◽  
Lei Chen ◽  
...  
Keyword(s):  
Pressure Wave ◽  
Dynamic Pressure

scholarly journals Research in a physical model with the top blowing of a gas-dynamic head and jet parameters at blowing of a liquid bath through an annular coaxial slit nozzle

2018 ◽  
Author(s):  
S.I. Semykin ◽  
T.S. Golub ◽  
S.A. Dudchenko ◽  
V.V. Vakulchuk
Keyword(s):  
Physical Model ◽  
Dynamic Pressure ◽  
Liquid Bath ◽  
Gas Jet ◽  
Oxygen Absorption ◽  
Equivalent Diameter ◽  
Depth Of Penetration ◽  
Gas Dynamic ◽  
Dynamic Head ◽  
Purge Gas

The aim of the work is to study the physical model of the gas-dynamic head of a gas jet and the parameters of its penetration into the liquid bath of the converter when it flows out of the annular slotted tuyere. The studies were carried out on a «cold» stand on a scale of 1:30 to a 160-m converter (taking into account the criteria of geometrical and physical similarity) using water as a liquid simulating a molten metal,. The averaged values of the depth of penetration of the gas stream of the jet at various blowing parameters were estimated. It is noted that when the upper purge through a coaxial slit nozzle with an increase in the pressure of the purge gas, the dynamic pressure of the depth of penetration of the jet increases. The increase in dynamic pressure and the depth of the introduction of a gas jet leads to an increase in the degree of impact on the bath and an increase in the degree of oxygen absorption by the melt. It was shown that, all other things being equal, the operation of a coaxial slit differs by a large impulse of exposure to a liquid than when blowing through an equivalent diameter slot through one centrally located nozzle, especially at pressures above 0.15-0.3 MPa. The possibilities of increasing the efficiency of the top blowing of the converter bath are shown through the use of a slotted coaxial nozzle.

scholarly journals Распространение одиночной волны давления по области разряда микроволнового диапазона длин волн в воздухе при средних давлениях

2021 ◽  
Vol 91 (11) ◽  
pp. 1641
Author(s):  
В.Л. Бычков ◽  
Л.П. Грачев ◽  
И.И. Есаков ◽  
А.В. Семенов
Keyword(s):  
Shock Wave ◽  
Wavelength Range ◽  
Delay Time ◽  
Pressure Wave ◽  
Focal Region ◽  
Initial Structure ◽  
Post Discharge ◽  
Discharge Mode ◽  
Gas Dynamic ◽  
Dynamic Pulse

Results of experiments on a propagation of a pressure wave with a shock-wave leading front through a gas region excited by a pulsed freely localized discharge of the microwave wavelength range are described. The discharge was realized in air at a pressure from 14 to 100 Torr in the focal region of a quasi-optical electromagnetic beam of the microwave wavelength range. The experiments revealed three types of interaction of the gas-dynamic pulse with the region excited by the discharge in the post-discharge mode. The specific type of interaction is defined by the initial structure of the discharge and the delay time of the gas-dynamic pulse passage through the excited region.

Gas Dynamic Design Analyses of Charging Zone for Reverse-Flow Pressure Wave Superchargers

2003 ◽  
Author(s):  
Pezhman Akbari ◽  
Norbert Mu¨ller
Keyword(s):  
Pressure Wave ◽  
Wave Equations ◽  
Reverse Flow ◽  
Flow Characteristics ◽  
Design Parameters ◽  
Expansion Waves ◽  
Gas Dynamic ◽  
Typical Configuration ◽  
Design Analyses ◽  
The Waves

The paper is focused on a comprehensive and systematic gas dynamic analysis of the high-pressure phase (charging zone) of pressure wave superchargers. The procedure is documented for a four-port reverse flow (RF) wave rotor, the typical configuration for engine wave superchargers, also named Comprex. A one-dimensional analytical gas dynamic model is employed to calculate flow characteristics inside the channels. Existing normal shock wave equations along with isentropic relations for expansion waves are used for calculations. Useful design parameters such as cycle timing and port widths are determined by formulating traveling times of the waves inside the channels. The gas dynamic study of the internal wave process demonstrates its fundamental dependence on the externally imposed compression ratio of the pressure wave supercharger.

Effects of Sensor Shape on Oscillating Pressure Measurements With Wind-Tunnel Test Confirmation

2006 ◽  
Author(s):  
David W. Wu ◽  
Hwang Choe
Keyword(s):  
Wind Tunnel ◽  
Pressure Sensor ◽  
Pressure Wave ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Wind Tunnel Test ◽  
Flow Patterns ◽  
External Flow ◽  
Pressure Measurements ◽  
Significant Correction

This paper summarizes the effects of the pressure sensor shape on the dynamic oscillating pressure measurements when the pressure wave modulating along the steam/air flow path is to be characterized. In the study presented in the paper, a three-dimensional CFD model of the external flow around the protruding, dome-shaped sensor was developed to evaluate the effects of the sensor shape on the external flow pattern, and the detailed flow patterns were studied with this protruding, dome-shaped sensors and compared with the flow patterns for the flush mounted sensors. Then, a one-dimensional analysis was done to predict that the dynamic pressures measured with the protruding sensor do not require significant correction, and this was later supported by wind tunnel tests. The amplitude of the dynamic pressure measured on the protruding sensor was determined to be ranging from 0 to 8% higher than measured by a flush mounted pressure sensor. The frequency of the pressure wave is not affected by the presence of the protrusion.

scholarly journals A Novel Dynamic Model for Predicting Pressure Wave Velocity in Four-Phase Fluid Flowing along the Drilling Annulus

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Xiangwei Kong ◽  
Yuanhua Lin ◽  
Yijie Qiu ◽  
Xing Qi
Keyword(s):  
Dynamic Model ◽  
Wave Velocity ◽  
Pressure Wave ◽  
Drilling Fluid ◽  
Dynamic Pressure ◽  
Mass Force ◽  
Virtual Mass ◽  
Influx Rate ◽  
Calculation Results ◽  
Phase Fluid

A dynamic pressure wave velocity model is presented based on momentum equation, mass-balance equation, equation of state, and small perturbation theory. Simultaneously, the drift model was used to analyze the flow characteristics of oil, gas, water, and drilling fluid multiphase flow. In addition, the dynamic model considers the gas dissolution, virtual mass force, drag force, and relative motion of the interphase as well. Finite difference and Newton-Raphson iterative are introduced to the numerical simulation of the dynamic model. The calculation results indicate that the wave velocity is more sensitive to the increase of gas influx rate than the increase of oil/water influx rate. Wave velocity decreases significantly with the increase of gas influx. Influenced by the pressure drop of four-phase fluid flowing along the annulus, wave velocity tends to increase with respect to well depth, contrary to the gradual reduction of gas void fraction at different depths with the increase of backpressure (BP). Analysis also found that the growth of angular frequency will lead to an increase of wave velocity at low range. Comparison with the calculation results without considering virtual mass force demonstrates that the calculated wave velocity is relatively bigger by using the presented model.

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