Controllable vibro – protective system for the driver seat of a multi – axis vehicle

The paper considers a controlled vibration protection of the multi-axis vehicle with hydraulic shock absorbers that are based on “smart” fluid. The dependence is experimentally determined for the viscous and elastic components of the resistance force of the electrorheological fluid as a function of intensity of the electric field. Investigation of vertical oscillations of the system “workplace-driver” with a controlled vibro-protection system is provided. The dependence is established for the relative displacement of weight as function of external perturbation at different values of the control signal

Dynamics of vibroprotecting system when using controlled damping fluids with hereditary factor

Oscillating system with a damper containing controlled damping fluid with hereditary electrorheological characteristics was investigated. Numerical calculation of the system in quasistationary approximation was carried out to prove the accuracy of applied assumptions

Исследования упругодемпфирующих характеристик виброзащитных систем с применением факторного эксперимента

The paper presents results of the investigations on elastic and damping characteristics of a vibration isolation system. Adequate mathematical models of relative root-mean-square values for acceleration of antivibration mass have been obtained depending on elastic and viscous constituents. The paper  reveals  that the proposed method of multiple correlation is the most rational one for the analysis of power  fluids used in the electro-rheological dampers.Представлены результаты исследований упругодемпфирующих характеристик виброзащитной системы. Получены адекватные математические модели относительных среднеквадратических величин ускорений виброзащитной массы в зависимости от упругой и вязкой составляющих. Показано, что предложенный метод множественной корреляции является наиболее рациональным для анализа рабочих жидкостей, применяемых в электрореологических демпферах

Дослідження роботи імпульсної двонаправленої турбіни в резонаторі термоакустичного апарата

Дослідження роботи імпульсної двонаправленої турбіни в резонаторі термоакустичного апарата = Study of operation bi-directional pulse turbines in the cavity thermoacoustie machine / В. В. Коробко, О. О. Московко, Г. Б. Мостіпаненко, С. І. Сербін // Авиационно-космическая техника и технология. – 2017. – № 8 (143). – С. 19–25.Використання низькотемпературних джерел теплової енергії (скидних або відновлювальних) є важливою задачею, оскільки сприяє підвищенню енергоефективності виробничих процесів та захисту довкілля. Термоакустичні апарати здатні забезпечити реалізацію цієї задачі, перетворюючи теплову енергію в механічну у вигляді потужних акустичних хвиль. Впровадженню термоакустичних систем на практиці заважає складність безпосереднього отримання механічної роботи або електроенергії від АХ. Використання імпульсних двонаправлених турбін (ІДТ) має сприяти вирішенню цієї проблеми. Шляхом експериментальних досліджень та CFD-моделювання вивчалися характеристики опитного зразка ІДТ, надано опис експериментального стенду, приведені результати експериментальних досліджень, визначені напрямки подальшої роботи.The use of low-temperature sources of thermal energy (waste or renewable) is an important task, as it improves the energy efficiency of production processes and in such way protects the environment. Thermoacoustic devices are capable to fulfill this task, converting thermal energy into mechanical energy in the form of powerful acoustic waves. The implementation of thermoacoustic systems in practice is hampered by the difficulty of obtaining mechanical work or electricity in these systems. The use of bi-directional turbines should help to solve this problem. Experimental prototypes and CFD-simulations were used for study the characteristics of the prototype bi-directional turbine along with the experimental stand description. The results of experimental studies and calculations were analyzed to find the routs for further work. eyo impulse bidirectional turbine, energy resources, thermoacoustics, thermal machines.Использование низкотемпературных источников тепловой энергии (сбросных или возобновляемых) является важной задачей, поскольку способствует повышению энергоэффективности производственных процессов и защиты окружающей среды. Термоакустические аппараты способны обеспечить реализацию этой задачи, превращая тепловую энергию в механическую в виде мощных акустических волн. Внедрению термоакустических систем на практике мешает сложность непосредственного получения механической работы или электроэнергии. Использование импульсных двунаправленных турбин (ИДТ) должно способствовать решению этой проблемы. В работе путем экспериментальных исследований и моделирования изучались характеристики опытного образца ИДТ, предоставлено описание экспериментального стенда, приведены результаты экспериментальных исследований и расчетов, определены направления дальнейшей работы

A Cryogenic Silicon Interferometer for Gravitational-wave Detection

The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of the existing LIGO observatory facilities, we have designed a new instrument that will have 5 times the range of Advanced LIGO, or greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby universe, as well as observing the universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor

The next detectors for gravitational wave astronomy

This paper focuses on the next detectors for gravitational wave astronomy which will be required after the current ground based detectors have completed their initial observations, and probably achieved the first direct detection of gravitational waves. The next detectors will need to have greater sensitivity, while also enabling the world array of detectors to have improved angular resolution to allow localisation of signal sources. Sect. 1 of this paper begins by reviewing proposals for the next ground based detectors, and presents an analysis of the sensitivity of an 8 km armlength detector, which is proposed as a safe and cost-effective means to attain a 4-fold improvement in sensitivity. The scientific benefits of creating a pair of such detectors in China and Australia is emphasised. Sect. 2 of this paper discusses the high performance suspension systems for test masses that will be an essential component for future detectors, while sect. 3 discusses solutions to the problem of Newtonian noise which arise from fluctuations in gravity gradient forces acting on test masses. Such gravitational perturbations cannot be shielded, and set limits to low frequency sensitivity unless measured and suppressed. Sects. 4 and 5 address critical operational technologies that will be ongoing issues in future detectors. Sect. 4 addresses the design of thermal compensation systems needed in all high optical power interferometers operating at room temperature. Parametric instability control is addressed in sect. 5. Only recently proven to occur in Advanced LIGO, parametric instability phenomenon brings both risks and opportunities for future detectors. The path to future enhancements of detectors will come from quantum measurement technologies. Sect. 6 focuses on the use of optomechanical devices for obtaining enhanced sensitivity, while sect. 7 reviews a range of quantum measurement options

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far