condition diagnostics of russian railways infrastructure constructions under aerodynamic loads from...

ISSN 0005-1179, Automation and Remote Control, 2014, Vol. 75, No. 3, pp. 580–586. © Pleiades Publishing, Ltd., 2014.Original Russian Text © S.M. Kaplunov, N.G. Valles, V.Yu. Fursov, A.M. Belostotskii, S.I. Dubinskii, 2012, published in Upravlenie Bol’shimiSistemami, 2012, No. 38, pp. 170–182.

LARGE SCALE SYSTEMS CONTROL

Condition Diagnostics of Russian Railways Infrastructure

Constructions under Aerodynamic Loads

from High-Speed Trains

S. M. Kaplunov∗, N. G. Valles∗, V. Yu. Fursov∗,A. M. Belostotskii∗∗, and S. I. Dubinskii∗∗∗

∗Blagonravov Institute for Machine Sciences, Russian Academy of Sciences, Moscow, Russia∗∗Science and Research Center StaDyO, Moscow, Russia

∗∗∗Moscow State University of Civil Engineering, Moscow, Russiae-mail: [email protected], [email protected], [email protected], [email protected], [email protected]

Received May 19, 2012

Abstract—Aim of the present research is realization of a complex procedure on the basis ofthe combined approach for modeling aerodynamic loads on elements of the infrastructure (sta-tion constructions and designs, pedestrian crossings, bridges and tunnels) at high speed trainspassage. Work is devoted to powerful methods of viscous gas currents modeling programsdevelopment and realization for research of aerodynamic loads on bodies making various move-ments, including shape variation, and to problems of bodies movement under aerodynamicforces solution.

DOI: 10.1134/S000511791403014X

1. INTRODUCTION

SJC “Russian Railways” has initiated the development of a technological platform “High-SpeedSmart Railway Transport” whose main objective is to develop a system of technical regulationsand national standards that would take into account worldwide experience of design, construction,and maintenance of high-speed railway transport that would allow to transport traffic according tothe best world practices.

2. METHODS FOR SOLVING THE PROBLEMS

The main project objective is to model and estimate aerodynamical loads on infrastructureelements when high-speed trains pass by; by infrastructure elements, we mean buildings on stations,pedestrian passes, bridges, and tunnels.

In the project we propose to use a combined approach based on the joint application of twomethods. The first is one of the most powerful and modern software for hydrogasodynamic compu-tations, ANSYS CFD, which implements the method of finite volumes to solve three dimensionalNavier–Stokes equations with a wide spectrum of turbulence models and settings (LES, DES, SASSST, RANS, and URANS ); it has been successfully verified by the developers on a wide range ofproblems for which we have test results in wind tunnels and prototype measurements [1, 3–8].

The actual aerodynamic computations were done with the software unit ANSYS CFX (calledCFX in what follows). The CFX unit lets the user model laminar and turbulent flows, compressibleand incompressible liquid, related heat exchange problems, multiphase flows, processes of boiling,burning, condensation, filtering, chemical reactions and so on. The unit supports more than twentydifferent turbulence models. The CFX unit does not include grid generators but rather lets oneimport grids prepared by other programs, in particular, by the ANSYS preprocessor with ANSYSAPDL parameterized macros.

580

CONDITION DIAGNOSTICS OF RUSSIAN RAILWAYS INFRASTRUCTURE 581

The second method is an original and effective Modernized Discrete Vortex Method (creation ofIMASH RAS) that lets one quickly solve a wide range of flow problems for rigid and elastic bodies ofvarious shape for a given range of Reynolds numbers in the numerical experiment; it was approvedwith known experimental data. Using this method, we find aerodynamical forces acting onmoving elements and multicomponent systems in infrastructure constructions (bridges, pedestrianpasses, pipe constructions, elastic station constructions) and also compute self- oscillations of theconstructions as high-speed trains pass by in the 2D setting [2, 9–12].

The main idea and innovativeness of the proposed method is to use a combination of these twoapproaches Using modern software and a lot of computational power, the first method lets us tosolve the proposed problem with the necessary accuracy and reliability in the 3D setting. Dueto very high computational load of these computations, even with a multicore computer it makessense to use the extensive experience in analytic computations and classical methods collected bythe Russian scientific school (the second method).

3. MAIN RESULTS

Existing software suites for computational hydrodynamics that use grid methods turn out to beinefficient in computations for constructions with changeable geometry. The computations in thiscase are prolonged. Therefore, it is a good idea to use vortex method with environmental modelswhich allow to find non-stationary loads in hydroelasticity problems with sufficient for engineeringcomputations precision and significantly smaller computational time expenditures.

The modernized discrete vortex method does not require grids construction, does not containempirical parameters, and allows to achieve high definition of flow structure. The method has lowscheme viscosity, and the numerical scheme is stable (there are no interruptions due to unboundedgrowth of variables). The developed method also significantly extends the capabilities of numericalstudies for the vortex formation mechanism and structure of non-stationary separated flow forarbitrary motion and shape changing of the flowed bodies; it is also useful in such problems as theoptimal choice of parameters for the cross section configuration.

The proposed modernized discrete vortex method can be applied to compute flow separationof single body that oscillates both along and across the flow, as well as in case of self-oscillationsinitiation and development. Method allows to define the width of the synchronization zone andamplitude-frequency characteristics of regime. This model also allows to consider the separationflow problem for a multicomponent construction, solutions of this problem, conceptually differ fromsingle body problem solution (Figs. 1 and 2).

Modeling experience with the discrete vortex method has shown that the resulting model has thefollowing advantages. On a unified mathematical and computational foundation, one can constructan entire hierarchy of software that is suitable for a wide range of applications. Based on thissoftware, together with a physical experiment we obtain important material which extends ourunderstanding and limits of applicability of these schemes and models are defined. Thus, we passfrom single problems to complex problems solution on system base.

Many years of experience in the development and application of the discrete vortex method hasshown that it has important advantages. Firstly, it has unique capabilities in constructing vortextraces and jets. Secondly, it contains an explicit stochastic mechanism (deterministic chaos) whichis important to model turbulence. Thirdly, the problem dimension is significantly reduced becausewe only need to watch track vortices on body surface and in trace but not in entire space.

For the first time we have obtained a formula to find aerodynamic forces acting upon an arbitraryprofile via instantaneous velocities of discrete vortexes in separated flow. Body may self-oscillatein the separated flow (Fig. 3).

AUTOMATION AND REMOTE CONTROL Vol. 75 No. 3 2014

582 KAPLUNOV et al.

Fig. 1. Dimensionless frequency of vortex separation for two pipes depending on distance between pipes. Blackdots indicate computed values; white dots, experimental values.

Fig. 2. Computed coefficients of hydrodynamic forces Cx, Cy change in time for each of the two tubes inseparated flow.

Fig. 3. Regions of dangerous states. On the left: self-oscillations amplitude for a gas pipe in water as afunction of the oscillations decrement δ and dimensionless flower velocity ω. On the right: dangerous velocitiesof inleakage flow depending on the pipe’s diameter d and span length L.



Fig. 4. Geometric surface model of Sapsan train’s front cars.

According to the developed algorithms, we have created original software which allows to performcomputations for long-term realizations of non-stationary hydrodynamic forces under separated flowaround bodies and systems of bodies that have various profiles and may oscillate both along andperpendicular to flow (Fig. 3). With this software, we have performed numerical experiments whichallow to find aerodynamic forces acting on moving infrastructure elements (bridges, passes, pipeconstruction, elastic station constructions) and compute self-oscillations of the constructions ashigh-speed trains pass by in 2D setting. To solve the boundary problem, we propose a universalcombined approach that joins together collocation and mirroring methods and allows computeseparated flow of a body with arbitrary cross section [2, 8–12].

We have identified critical air flow velocities as function of dimensionless parameters whichinclude oscillations’ logarithmic decrement value and the eigenfrequency of the body’s oscillations.We have identified the regions of admissible operation conditions for all cases of constructionsoscillations exciting in a wide range of flow velocities (Fig. 3).

In this work, we show a description of the created voluminous models of a high-speed trainintended to find aerodynamic parameters, including choosing the best methodologies to constructcomputational grids, turbulence models, parameters and options for computational algorithms inapplication to a given class of problems and the chosen basic software suite (Fig. 4). We apply theprocedures for passing aerodynamic loads to the software that computes dynamics and durabilityof constructions together with implementing and verifying the “engineering” approach to estimatethe values and zones where pressure extremely arises.

The resulting software allows, unlike existing software, to get in a short time characteristicparameter of complex amplitude-frequency characteristics (especially for nonlinear systems) forbodies oscillations. It also allows to find, for the processes under consideration and various typesof multicomponent systems (with different number of supports with clearances and span lengthsbetween them) parameters that important for the design, operation, and resource forecasting.

Our results allows to find zones for top priority monitoring and diagnostics for constructionsflowed around by wind on a station. They also allows to propose promising approaches and tech-nological activities in order to improve endurance and durability of the considered important con-structions.

4. APPLICATIONS OF OUR RESULTS IN THE APPROVED TECHNOLOGICALPLATFORM “HIGH-SPEED SMART RAILWAY TRANSPORT”

Proposed approach has the following advantages and characteristic features:

—a combined approach is original in sense of interrelated use of two modern computationalmethods for effective solution of aerodynamic problems in 3D and 2D settings and has no analogiesin interconnection realization;


584 KAPLUNOV et al.

Fig. 5. Computational Karman vortexes trace for a bridge over a railway. Wind flow is parallel to the Earthsurface.

Fig. 6. Computational Karman vortexes trace for two complex configuration bodies under separated air flow.

Fig. 7. Computational Karman vortexes trace for two cylinders with square cross-sections.

—it allows to perform dynamic analysis based on computational results for hydrodynamic loadsand force interaction coefficients for single- and multicomponent constructions using numericalexperiment for the entire range of possible flow velocities as well as for forces oscillations andself-oscillations of the constructions, this significantly increases its efficiency (Figs. 2 and 3);

—our approach allows to obtain necessary data without complicated and expensive full scalephysical experiment, come to nothing more than special physical modeling tests on hydrodynamic



testbed in accordance with its capabilities; this significantly reduces the labor intensity and oper-ating costs for investigation;

—proposed approach also allows, basing on already existing and developing in our project algo-rithms and software to obtain optimal parameters combinations for cross section configuration inflow (Figs. 5–7);

—the proposed realizing computation complex allows to determine the necessary measures andcorresponding constructive changes for the required system rigidity regulation for instance by meansof additional intermediate supports and clearances choice.

Thus, proposed approach is intended to increase significantly the construction durability. Itwould be widely used in state forecasting and monitoring of infrastructure complexes and buildingon critical segments of Russian Railways; it corresponds to the world level of research activitiesdevelopment in this domain of knowledge.

Obtained results allow to find zones that should be primary targets for monitoring and diag-nostics among station constructions forced by air flow. They also let us to propose promising waysand technological activities to improve endurance, wear resistance, and durability of the consideredimportant constructions.

As a result, frequency tuning out in these cases can be performed reliably and correctly if thefollowing problems for the considered construction in flow are solved:

(1) Strouhal numbers for body in wind flow were determined;

(2) parameter region, where turbulence mechanism of oscillations exciting obtain maximumvalue, was determined;

(3) intensity of oscillations, excited by turbulence estimation was carried out.

ACKNOWLEDGMENTS

This work was supported by the Russian Foundation for Basic Research, project no. 11-08-13119-ofi-m-2011-RZhD.

REFERENCES

1. Belostotskii, A.M., Dubinskii, S.I., Kalichava, D.K., Pen’kovoi, S.B., Potapenko, A.L., andKlepets, O.Ju., Composite Computational Analysis of the Strain and Stress Distribution for High-RiseMultipurpose Complexes, Stroitel. Mekh. Raschet Sooruzhen., 2006, no. 10, pp. 99–110.

2. Valles, N.G., Computing of Cylinder Separated Flow under Self-oscillations in a Frictionless FluidStream, Mekh. Zhidk. Gaza, 1980, pp. 174–178.

3. Dubinskii, S.I., Numerical Simulation of Wind Loads on Tall Buildings at “Moscow-City,” Int. J. Com-put. Civil Struct. Eng., 2008, vol. 4, no. 2, pp. 58–59.

4. Dubinskii, S.I., ANSYS 8.0: A Survey of New Capabilities, SAPR Grafika, 2003, no. 11, pp. 42–44.

5. Dubinskii, S.I., The Software Suite ANSYS LS-DYNA 8.0, SAPR Grafika, 2004, no. 3, pp. 34–38.

6. Dubinskiy, S.I., ANSYS and ANSYS/CivilFEM in Construction, SAPR Grafika, 2004, no. 12, pp. 75–77.

7. Dubinskii, S.I., Computations for High-Rise Constructions under Wind Influence, SAPR Grafika, 2005,no. 10, pp. 32–34.

8. Dubinskii, S.I. and Serebrennikova, A.V., Numerical Modeling of Wind Aerodynamics in PedestrianZones of High-Rise Buildings, in Sb. tr. Mezhd. nauchn.-prakt. konf. “Teoriya i praktika rascheta zdanii,sooruzhenii i elementov konstruktsii. Analiticheskie i chislennye metody” (Proc. Int. Sci.-Pract. Conf.“Theory and Practice of Computing Buildings, Constructions, and Construction Elements. Analyticaland Numerical Approaches”), November 12, 2008, Moscow: MGSU, pp. 259–266.


586 KAPLUNOV et al.

9. Kaplunov, S.M., Valles, N.G., Gorelov, E.V., and Shitova, L.I., Mathematical Model Approach of Hydro-dynamic Vibration Generation Mechanisms of Heat-Exchange Tube Bundles, Probl. Mashinostr. Nadezh.Mash., 2008, no. 3, pp. 107–112.

10. Kaplunov, S.M., Valles, N.G., and Shitova, L.I., Application of Discrete Vortexes Method to Computingof Tube in Liquid Flow Self-Oscillations, Probl. Mashinostr. Nadezh. Mash., 2009, no. 4, pp. 13–18.

11. Kaplunov, S.M., Makhutov, N.A., Valles, N.G., Fesenko, T.N., and Panov, V.A., Promising Directions inComputational Studies of Dynamics and Durability of Multicomponent Fragments of Constructions ofWater–Water ER, in Sb. tez. VI Mezhd. nauchn.-tekh. konf. “Obespechenie bezopasnosti AES s VVER”(Proc. VI Int. Sci.-Tech. Conf. “Providing Safety in Nuclear Power Plants with Water–Water EnergicReactor”), OKB “Gidropress, 2009, p. 123.

12. Frolov, K.V., Makhutov, N.A., Kaplunov, S.M., Smirnov, L.V., et al., Dinamika konstruktsii gidroaer-ouprugikh sistem (Dynamics of Constructions of Hydroaeroelastic Systems), Kaplunov, S.M. andSmirnov, L.V., Eds., Moscow: Nauka, 2002.


condition diagnostics of russian railways infrastructure constructions under aerodynamic loads from...

Documents