Simulation of stresses and contact surfaces of disk rolling cutters with the rock when sinking in mixed soils

In this paper, we consider the crack propagation in the rocks during sinking depending on the distance between the cutters. Under the same conditions, the hard and soft rocks form various fracture networks that leads to uneven sinking and decrease in the efficiency of the tunneling machine. In order to study this issue, four ranges of distance between the contact surfaces and various incidence angles of the contact surface were selected. The study includes a system that is a mountain mass layout with a disk cutter the only parameter of which is the tip width or the contact width of the disk cutter with the end-type rock. Simulation of research conditions and finding a solution to the problem were performed using the Autodesk Inventor Nastran 3D simulation software

CFD and Experimental Simulation of the Laminar- Turbulent Transition on the HEXAFLY-INT Glider Model

status: publishe

A high-power source of ultrawideband radiation with reflector antenna

Characteristics of a source of linearly-polarize

A high-power source of ultrawideband radiation with reflector antenna

Characteristics of a source of linearly-polarize

Numerical and Experimental Aerodynamic Characterization of the HEXAFLY-INT Hypersonic Glider

© 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. As a fundamental step towards the development of a civil high-speed transport concept, the European Community (EC) co-funded HEXAFLY-INT international project (with partners from Europe, Russian Federation, Brazil and Australia), has the aim to design, manufacture and test in flight an innovative gliding hypersonic vehicle, based on the configuration developed in previous EC co-funded projects LAPCAT I, II and HEXAFLY. The flight experiment is focused on a self-controlled glider configuration characterized by high aerodynamic efficiency and equipped with several breakthrough technologies on-board, in order to provide valuable aerodynamic and aero-structural flight data to validate methods and technologies used to design the hypersonic vehicle. In this framework, this paper provides a detailed overview on research efforts carried out in assessing the aerodynamic performance of the expendable Experimental Flight Test Vehicle under development in the programme. Aerodynamic results are obtained by means of a massive number of CFD simulations of increasing level of accuracy and through an experimental test campaign carried out at TsAGI in their T-116 wind tunnel facility.status: publishe

Boundary Layer Transition Assessment on a Slender High-Speed Vehicle

© 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. To anticipate the aerodynamic performance of a slender high-speed vehicle throughout a trajectory, the correct determination of transition onset and extent are crucial parameters in the overall evaluation. Though various methods and correlations are worked out on canonical geometries such as flat plates and cones, the present paper will primarily focus on a slender high-speed vehicle concept. Apart from small leading edge radii and 3D flow effects, also practical considerations are included such as gaps and steps indivertibly present due to manufacturing and integration, differential thermal expansion at dissimilar material interfaces, joints etc. A preliminary assessment based on empirical correlations is challenged by a detailed experimental campaign supported by numerical CFD computations. Their applicability range and their limitations are assessed related to the observed flow phenomena.status: publishe

Hydrological, meteorological observations and isotopes sampling results during 2019-2020 at Djankuat Glacier Station in the North Caucasus, Russia

This is an update of a dataset on the long-term complex glaciological, hydrological, meteorological observations and isotopes sampling in an extremely underreported alpine zone of the North Caucasus. The Djankuat research basin is of 9.1 km2, situated on elevations between 2500 – 4000 m, by 30% covered with glaciers. The biggest in the basin Djankuat glacier was chosen as representative of the central North Caucasus during the International Hydrological Decade and is one of 30 'reference' glaciers in the world that have annual mass-balance series longer than 50 years (Zemp et al, 2009). The original dataset covers 2007-2017, this update - 2019-2020. In total, the dataset contains the result of yearly measurements of snow thickness and density; dynamics of snow and ice melting; measurements of water runoff, conductivity, turbidity, temperature, δ18O, δ2H on the main gauging station with a one-hour or several-hours step depending on the parameter; data on δ18O and δ2H sampling of liquid precipitation, snow, ice, firn, groundwater in different parts of the watershed regularly in time during the melting season; precipitation amount, air temperature, relative humidity, shortwave incoming and reflected radiation, longwave downward and upward radiation, atmospheric pressure, wind speed and direction – measured on several automatic weather stations within the basin with 15 min – one-hour step; gradient meteorological measurements to estimate turbulent fluxes of heat and moisture, measuring three components of wind speed at a frequency of 10 hertz to estimate the turbulent impulse heat fluxes over the glacier surface by the eddy covariance method. The observations were held during ablation period June-October and were interrupted in winter. The dataset will be further updated. The dataset can be useful for developing and verifying hydrological, glaciological and meteorological models for high elevation territories, to study impact of climate change on hydrology of mountain regions, using isotopic and hydrochemical approaches to study mountain territories