О формировании разломов Мало-Ботуобинского района Якутской алмазоносной провинции (результаты физического моделирования)

The article discusses the features and results of physical and mathematical modeling of filtration experiments on terrigenous and carbonate rock core samples at different crimping pressures. Such studies are necessary to understand the effect of rock pressure on the reservoir properties and relative phase permeability (RP) of reservoir rocks, including from the standpoint of the Digital Core technology, since core tomography is usually performed under atmospheric conditions and data on rock properties are required for reservoir conditions. The article discusses the features and results of physical and mathematical modeling of filtration experiments on terrigenous and carbonate rock core samples at different crimping pressures. Such studies are necessary to understand the effect of rock pressure on the reservoir properties and relative phase permeability (RP) of reservoir rocks, including from the standpoint of the Digital Core technology, since core tomography is usually performed under atmospheric conditions and data on rock properties are required for reservoir conditions. The laboratory study of the relative permeability was carried out on composite core models by the method of stationary filtration at crimping pressures of 10 and 20 MPa. Mathematical modeling of filtration experiments was performed in the Eclipse simulator. The distribution of porosity in the hydrodynamic models of the core was set based on data from computed tomography of the core. The distribution of other rock properties (permeability, residual saturations, RPP values at residual saturations) was calculated using generalized dependencies. It is shown that for terrigenous and carbonate rocks, an increase in pressure leads to different behavior of the RPP functions and fluid mobility. The results of laboratory studies are interpreted from the point of view of processes at the micro level, based on the formation of the nature of the flow and the associated water saturation during deformation of the void space. It is also shown that filtration experiments on core at different rock pressures can be simulated on a hydrodynamic simulator, but at the same time, the study of patterns in the change in model parameters with a change in pressure depends on the presence of patterns in the behavior of rock properties based on the results of physical modeling.

The Zuppinger water wheel, developed in the 1850s, is one of the most efficient water wheels and is commonly used for low-head hydropower generation. The high efficiencies of the wheel over a wide operating range, its simplicity in design and slow rotational speed offer a low-cost and environmentally friendly low-head hydropower solution. A physical and numerical model study of a wheel is presented in this paper. Three-dimensional numerical simulations were performed using the computational fluid dynamics (CFD) code Flow-3D. The influence of grid size on the results of the numerical model was assessed using a systematic grid refinement study. Grid convergence indices (GCIs) were calculated for two grid sets each, with three different grid sizes, using a constant grid refinement ratio. The GCIs were reduced to levels below 5% for the selected quantities of interest. The CFD model results were compared with physical model results at different operating points of the wheel. The maximum differences in power output and efficiency between the physical and numerical model results were 2.5% and 8%, respectively.

Based on a new approach, profiles of kinetic temperature and atmospheric pressure between 20 and 116 km altitude and CO2 and CO volume mixing ratios between 70 and 116 km have been derived from the ∼0.01‐cm−1 resolution infrared solar occultation spectra recorded by the atmospheric trace molecular spectroscopy (ATMOS) Fourier transform spectrometer during the Spacelab 3 shuttle mission (April 29 to May 6, 1985). The physical model and CO2 profile results have been obtained from simultaneous multiscan least squares fitting of microwindows containing CO2 lines with temperature‐dependent and temperature‐independent intensities and N2 lines with temperature‐independent intensities. The analysis included the retrieval of tangent height separations between spectra in the lower stratosphere, where independent information shows drifts of the sun tracker field of view on the solar disk. The physical model results are compared with climatological profiles, lower thermospheric temperatures computed with the MSISE‐90 model, and other data. The CO2 retrievals indicate a nearly constant volume mixing ratio of 320 ± 35 ppmv (parts per million, 10−6, by volume) in the 70‐to 90‐km altitude region with a rapid decline in the CO2 volume mixing ratio beginning between 90 and 100 km; at 116 km the CO2 volume mixing ratio has declined to about 70 ppmv and is equal to the CO volume mixing ratio, which has been derived from fits to the (1‐0) CO vibration‐rotation band. The absorption by the v2 + v3 ‐ v2 band of CO2 has been analyzed to quantify nonlocal thermodynamic equilibrium (non‐LTE) effects in the upper mesosphere and lower thermosphere. Up to an altitude of 100 km, the results indicate that the vibrational temperature of the v2 state of CO2 is within 5 K of the kinetic temperature. At higher altitudes, non‐LTE effects are observable with the vibrational temperature of the v2 state cooler than the kinetic temperature by 40 K (48°S) and 70 K (30°N) at 112 km. Above 112 km, lines of the v2 + v3 ‐ v2 band are too weak to be observed in the ATMOS spectra.

Physical and numerical models were used to assess ice passage at navigation locks, focusing on key factors such as the design of the lock filling and emptying system and the intakes to the lock filling culverts. Unconventional ice passage techniques such as manifolds in the miter gates were also evaluated. Physical model results were compared to field observations and to a parallel series of tests using the DynaRICE ice-hydraulic numerical model. The study focused on three general ice processes at locks: (1) ice accumulating near culvert intakes during lock filling; (2) drawing ice into the lock chamber; and (3) flushing ice out of the lock. Ice accumulation thickness in the upper lock approach was found to be the most important parameter affecting ice passage into the lock chamber. Physical and numerical model results compared reasonably well, proving DynaRICE to be a useful tool for assessing ice passage for new lock designs.

The article deals with problems of using of measurement method Particle Image Velocimetry (PIV) to measure velocity fields in the flowing water in front, above and behind drowned titling weir gate. The aim was to obtain information about the distribution of speed in the area of interest for the verification or calibration of the numerical model. Experiments were carried out in inclinable channel connected to the hydraulic circuit with a pump and storage tank at the Water Management Research Laboratory (LVV) of Institute of Water Structures at the Faculty of Civil Engineering in Brno University of Technology. Hydraulic inclinable channel has cross-section with dimensions of 0.4x0.4m and length of 12.5m. The measured area has cross-section approximately 0.2m wide and 0.4m high and its length is 1m. The results of physical modelling allowed a comparison of experimental data with numerical simulation results of this type of flow in the commercial software ANSYS CFX-12.0. In the foreground interest in the field of water management still more are getting and applying options of numeric modeling, mainly based on very rapid development of the performance of personal computers. Using the numerical simulations of fluid flow, we are today able to obtain detailed information about all characteristics of the flow required for optimal design of waterwork. However, a significant disadvantage of numerical simulation is the necessity to obtain initial and marginal (boundary) conditions that must be entered as input data into the computer calculation program. These input data is in most cases can be obtained only on the basis of physical modeling, so measurements characteristics of flow on the physical model. The results of numerical simulations must be compared with the results of physical modelling and on the base it calibrated the numerical model. To determine the characteristics of liquid flow respectively velocity field on the physical model appears to be an ideal method of PIV (Particle Image Velocimetry), which allows us a sufficiently accurate measurement velocity field of fluid flow in the selected area.

Platform structures are commonly utilized for various purposes including offshore drilling, processing, and support of offshore operations. A jacket is a supporting structure for deck facilities, stabilized by piles driven through it to the seabed. In a jacket design, operational and environmental loads are very important and must be intensively investigated to secure the stability of structures during their service life, as well as installation phase. The main purpose of this research is to evaluate the results of physical modeling for the launch operation of jackets from barge into the sea, as the most hazardous stage in the installation of a platform, and compare them to those of numerical modeling. Both physical and numerical modeling parameters are described and they are examined on a prototype platform, i.e., Balal oil field production and living quarter platform that is a 1700 tone, eight-legged jacket located in the center of Persian Gulf, some 100km distance from Iranian Lavan Island. It is found that both numerical and physical methods can describe the motion of the barge similarly well, but some differences are traced in the motion of jacket. The inequalities are, then, appeared to be due to the Froude-type parameters applied for modeling purpose. One notable fact investigated in this research is the necessity for choosing Reynolds–Froude type in the physical modeling of the launch, instead of Froude type. This is because, in addition to the importance of gravitational and inertial forces, the viscosity affects the drag hydrodynamic force, as well. It should be noted that viscosity and consequently drag coefficient in Froude type modeling cannot be quite applicable and this causes the difference observed between the results of physical and numerical modeling. Although there have been so many jacket launching designed and probably their physical models have been tested, but to the best of our knowledge from the literature, there was found no study on Reynolds–Froude physical modeling of jacket launch phenomenon. If one is interested in practicing a Reynolds-Froude physical modeling, it could be done either in a centrifuge test or by using a fluid with lower viscosity dependent on the scale of model, or even by finding a fluid (with new viscosity and new density) and a new gravity to have simultaneously the Froude and the Reynolds similarity laws satisfied.

The article describes the mechanism of formation and development of subseismic-scale faults in sedimentary rock mass based on results of physical and mathematical simulation. Physical modelling of layered rock massif was carried out by using sand-gypsum mixture. The results of physical modeling made it possible to visually evaluate the process of formation and development of subseismic-scale faults, to establish the orientation and amplitude of the modeled faults. It was established that faults with higher amplitude had filler material formed because of friction of fault edges/walls. The volume of modelled formation after formation of faults depending on fault amplitudes changed from 2-3 to 10 %. To gain information on stress deformed condition of rock massif and identification of key peculiarities of fault propagation dynamics we used the mathematical modeling based on particle-flow algorithm. The results of mathematical modeling determined that during formation of low amplitude faults the shear field has several rock clusters. Due to interaction of clusters, which have coordinated movement and promote massif loosening, the rock mass accumulates voids, which are the prerequisite for formation of subseismic-scale faults. The gained results enable to specify the complex mechanism of irreversible shears and deformations of rock mass during formation and development of subseismic-scale faults. It contributes to the improvement of the methodology for predicting the SSF parameters, which is of practical importance in terms of reducing mining risks.

The results of physical and numerical modeling to determine the rate of evaporation of ethanol, at a flow of air flow velocities in the range of 0.0139 - 0.139 m/s and temperature in the range of 10 - 45 °C are placed. The time of the establishment of the diffusion equilibrium in the work area and differences in the results of numerical and physical modeling are have determined.

Statistical analysis of bimslope stability using physical and numerical models

Platform structures are commonly utilized for various purposes including offshore drilling, processing and support of offshore operations. A jacket is a supporting structure for deck facilities stabilized by leg piles through the seabed. In a jacket design, operational and environmental loads are very important and must be investigated intensively to secure the stability of structures during their operational life, as well as installation phase. The main purpose of this research is to evaluate and compare the results of physical and numerical modeling for the launch operation of jackets from barge into the sea, as the most hazardous stage in the installation of a platform. Both physical & numerical modeling basics are described and they are performed on Balal PLQ (Production and Living Quarter) platform that is one 8-legged, 1700-tone main jacket of Balal oil field, located in the center of Persian Gulf, some 100 kms distance from Iranian Lavan Island. It is found that both methods can describe the motion of the barge similarly well, but some differences are traced in the motion of jacket. Then, the inequalities are evaluated to be due to the Froude-type parameters chosen for modeling purpose. The most important result achieved in this research is the necessity of choosing Reinolds-Froude type for physical modeling of launching, instead of Froude-type. This is due to the effect of viscosity in drag hydrodynamic force in addition to the importance of gravitational and inertial forces. It should be noted that viscosity and consequently drag coefficient in Froude type modeling is not quite correct and causes the difference between the results of physical and numerical modeling. To our knowledge, based on the surveyed done in the literature, although there was no results found on the physical modeling of jacket launch to be addressed, but it seems that Reynolds-Froude modeling could be done either in a centrifuge test or by using a fluid with lower viscosity dependent on the scale of model.

The chapter contains materials on elucidating the influence of the shape of the top of the rod electrode and the value of the applied electric field strength on the presence and value of the corona current on top of the grounded electrode. Physical modeling was used. The purpose of these experiments was to establish a correlation between the results of physical and mathematical modeling of electromagnetic processes during the development of corona discharges in order to verify the adequacy of the description by a mathematical model of the processes of the appearance of the corona, as well as their degree of intensity, due to the value of the corona current. The results of physical modeling of electromagnetic processes during the development of the corona on rod electrodes with tops of various shapes are presented, using which mathematical models of the processes of corona formation on the tops of rod electrodes are constructed.

Introduction (problem statement and relevance). The article describes a physical model of a road train with active drive of semi-trailer wheels. The results of research tests of the physical model are given, with the help of which the adequacy of the mathematical models of dynamics of the road train as a part of a truck tractor and semi-trailer with active wheel drive is evaluated. The purpose of the study is estimation of efficiency of the technical solutions aimed at increase of vehicle passability and maneuverability.Methodology and research methods. In the course of the study the method of analysis of results of tests of the operating active road train scaled mock-up, the method of comparative analysis of the results of mathematical and physical modelling have been used. Scientific novelty and results. The performed studies confirmed correlation of the physical and mathematical modelling results, as well as indicated that the use of physical modelling serves as an efficient method to obtain an objective assessment of operational properties of the designed road train. The article considers constraints and limitations of using a scalable vehicle to study its dynamics. Matters of model parameters validity, conditions for dynamic similarity, and physical modelling results for active road train dynamics are given.Practical significance. Physical modelling of a (full-)scale sample using a scaled model reduces the costs and time when developing an active road train with new technical solutions, and increases reliability of the results obtained through the mathematical and physical modelling.

The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (themore » ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.« less

Theoretical and experimental investigations of the ultrasonic exposure (USE) frequency impact on the liquid evaporation process are carried out. Investigations were carried out under reduced pressure in a vacuum chamber. A refined physico-mathematical model of the USE thermodynamic process is developed. The dependences of the change in mass and temperature of various liquids (distilled water, alcohol mixture, kerosene TS-1) on the USE frequency and external pressure are obtained. The effect of a sudden liquid “explosion” at certain USE frequency and external pressure values is discovered. The results of physical and mathematical modeling are obtained as the dependence of the change in liquid temperature on the USE frequency and external pressure. The results of physical and mathematical modeling and experimental research are analyzed and compared. The obtained results can be used for drying various materials and cleaning surfaces.

The destruction of ground dams, of natural and artificial origin, is caused by certain critical conditions. The main reasons for this are the overflow of water over the crest of a dam, the filtration of water through its body, or mechanical destruction. The processes of destruction of ground dams of moraine lakes are very frequent phenomena for mountain regions and can often occur there. In addition, the outburst of ground dams can take place under the thickness of the cover and mountain glaciers that leads to the formation of the subglacial hydrographic drainage system. Because of the dam destruction, outburst floods, which are accompanied by significant destruction and even human losses, are formed. Considering that, it is extremely difficult and unsafe to investigate the outburst process directly at the time of its natural occurrence, the researchers turn to alternative methods, like physical modeling. In this paper, the results of physical modeling of the outburst of the moraine model reservoir are presented. The experiment was carried out near the coastline of the outburst glacier lake Bashkara (Central Caucasus, Elbrus Region, Russia). Therefore, the artificial dam, consisting of material of moraines surrounding the lake, was created. This leads to a possibility to recreate the experimental conditions closest to natural. During the research photography and video filming of the outburst of the model reservoir were carried out. The results of physical modeling are in complete agreement with previously published data of outburst of ground dams and do not contradict with the physical essence of the process.