Choice of a turbulence grid and model to calculate the discharge coefficient of the standard orifice plate

The results of analyzing a flow in the measuring pipeline with a standard orifice plate within the range of 5×10⁴ ≤ Re ≤ 10⁸ using the computational fluid dynamics (CFD) methods are presented. A deviation of the design value of the discharge coefficient from the value indicated in the standard served as a criterion for choosing a turbulence model and grid. The calculation data for the discharge coefficient obtained with the use of RANS turbulence models are given and it is shown that the CFD methods make it possible to calculate the discharge coefficient of a variable-pressure drop flowmeter with a precision that meets the standard requirements.     

Stress analysis of helicopter main rotor torsion bar

The results of stress analysis for the main rotor torsion bar of the ANSAT helicopter based on the finite element method are presented. The analysis was performed for the base types of loading in the linear statement. The analysis results agree well with the experimental data.     

Gravitational and hydroelastic waves in thomson-delaney cells of the ocean on Jovian Moon Europa

The possibility of appearance of hydrothermal cells in the system “Ocean of Jovian Moon Europaits ice crust” was theoretically proved by R. Thomson and J. Delaney [8]. We formulated in [11] boundary value problems for planetary gyroscopic waves and gravitationally elastic waves in these cells, and the spectrum of nondivergent gyroscopic waves was numerically investigated. The present paper is a continuation of [11]. It considers the spectra of independent, purely gravitational and hydroelastic waves. The possibility of resonant excitation in Thomson-Delaney cells of gravitational and hydroelastic waves is considered.     

Operations of a spaceflight experiment to investigate plant tropisms

Plants will be an important component in bioregenerative systems for long-term missions to the Moon and Mars. Since gravity is reduced both on the Moon and Mars, studies that identify the basic mechanisms of plant growth and development in altered gravity are required to ensure successful plant production on these space colonization missions. To address these issues, we have developed a project on the International Space Station (ISS) to study the interaction between gravitropism and phototropism in Arabidopsis thaliana. These experiments were termed TROPI (for tropisms) and were performed on the European Modular Cultivation System (EMCS) in 2006. In this paper, we provide an operational summary of TROPI and preliminary results on studies of tropistic curvature of seedlings grown in space. Seed germination in TROPI was lower compared to previous space experiments, and this was likely due to extended storage in hardware for up to 8 months. Video downlinks provided an important quality check on the automated experimental time line that also was monitored with telemetry. Good quality images of seedlings were obtained, but the use of analog video tapes resulted in delays in image processing and analysis procedures. Seedlings that germinated exhibited robust phototropic curvature. Frozen plant samples were returned on three space shuttle missions, and improvements in cold stowage and handing procedures in the second and third missions resulted in quality RNA extracted from the seedlings that was used in subsequent microarray analyses. While the TROPI experiment had technical and logistical difficulties, most of the procedures worked well due to refinement during the project.     

Parametric excitation of gyroscopic waves in Thomson-Delaney cells of the ocean of Jovian moon Europa

A possible mechanism (of parametric resonance type) of excitation of planetary gyroscopic waves in Thomson-Delaney cells of the ocean of Jovian moon Europa is considered. It is assumed that the basis of this mechanism is a variation of liquid depth in a cell caused by tidal oscillations under the action of gravitational perturbing influence of Galilean satellites of Jupiter. Such a model leads to a system of linear differential equations with periodic coefficients of the Hill’s type. Under some additional assumptions it changes over into a system of independent Mathieu equations. The regions of parametric resonance of this system are constructed.     

Wing stressed state in the region of torque discontinuities

A problem of determining the stressed state of the thin-walled beam in the zone of deplanation constraint caused by a torque discontinuity is considered using Odinokov’s formulation of mutually-balanced end loading.     

Application of oil dispersion to enhance the efficiency of aircraft GTE oil system operation

The data obtained in the course of experimental studies of a promising technique for the MS-8P engine oil cleaning by its dispersion are presented. It is obtained that as a result of dispersion, the sizes of solid particles in oil appearing in the process of wear of the triboengineering system elements in the aircraft GTE rotors do not exceed 3 μm making it possible to increase the engine oil service life and durability of rotor bearings.