Numerical Procedure for the Three-Dimensional Nonlinear Modelling of Composite Steel–Concrete Beams

An automatic approach for the multi-objective shape optimization of microgas turbine heat exchangers is presented. According to the concept of multidisciplinary optimization, the methodology integrates a CAD parametric model of the heat transfer surfaces, a three-dimensional meshing tool, and a CFD solver, all managed by a design optimization platform. The repetitive pattern of the surface geometry has been exploited to reduce the computational domain size, and the constant flux boundary conditions have been imposed to better suit the real operative conditions. A new approach that couples cold and warm fluids in a periodic unitary cell is introduced. The effectiveness of the numerical procedure was verified comparing the numerical results with available literature data. The optimization objectives are maximizing the heat transfer rate and minimizing both friction factor and heat transfer surface. The paper presents the results of the optimization of a 50kWMGT recuperator. The design procedure can be effectively extended and applied to any industrial heat exchanger application.

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Study of composite steel-concrete beams under negative bending moment

10.1063/5.0066947 ◽

2022 ◽

Author(s):

Ali Hussam Ali ◽

Hayder Wafi Ali Al-Thabhawee

Keyword(s):

Concrete Beams ◽

Bending Moment ◽

Negative Bending ◽

Composite Steel

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Three-Dimensional Finite Element Analysis of Pipe Flange Connections: The Case of Using Compressed Asbestos Sheet Gasket

Analysis of Bolted Joints ◽

10.1115/pvp2002-1095 ◽

2002 ◽

Cited By ~ 1

Author(s):

Tomohiro Takaki ◽

Toshimichi Fukuoka

Keyword(s):

Contact Pressure ◽

Three Dimensional ◽

Numerical Procedure ◽

Bending Moment ◽

Elastic Interaction ◽

Bearing Surface ◽

Element Analysis ◽

Bolt Stress ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element

The most important factor for the leakage problem of pipe flange connections is considered to be contact pressure distribution at the gasket bearing surface in service. In this study, the mechanical behaviors of the pipe flange connection are evaluated using FEM as a three-dimensional contact problem, in which a gasket is modeled as a nonlinear one-dimensional gasket element. Here, the contact pressure distributions at the gasket bearing surface and the variations of the bolt stress are estimated under uniform bolt preloads or nonuniform ones due to the elastic interaction during bolting up. The numerical procedure proposed here can successively deal with the processes of bolt-up, applying inner pressure and applying bending moment. The analytical objects are pipe flanges specified in JIS B 2238 with compressed asbestos sheet gaskets being inserted. The validity of the numerical method is ascertained by experiment.

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Behaviour of composite steel-concrete beams under elevated temperatures

From Materials to Structures: Advancement through Innovation ◽

10.1201/b15320-27 ◽

2012 ◽

pp. 155-160

Author(s):

K Wilkins ◽

O Mirza ◽

B Uy

Keyword(s):

Elevated Temperatures ◽

Concrete Beams ◽

Composite Steel

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Numerical simulation of complex 3D compressible viscous flows through rotating blade passage

Theoretical and Applied Mechanics ◽

10.2298/tam0301055d ◽

2003 ◽

pp. 55-82

Author(s):

M. Despotovic ◽

Milun Babic ◽

D. Milovanovic ◽

Vanja Sustersic

Keyword(s):

Stokes Equations ◽

Three Dimensional ◽

Numerical Procedure ◽

Convergence Acceleration ◽

Design Tool ◽

Navier Stokes ◽

Internal Flows ◽

Navier Stokes Equations ◽

Rotating Blade ◽

Compressible Viscous Flows

This paper describes a three-dimensional compressible Navier-Stokes code, which has been developed for analysis of turbocompressor blade rows and other internal flows. Despite numerous numerical techniques and statement that Computational Fluid Dynamics has reached state of the art, issues related to successful simulations represent valuable database of how particular tech?nique behave for a specifie problem. This paper deals with rapid numerical method accurate enough to be used as a design tool. The mathematical model is based on System of Favre averaged Navier-Stokes equations that are written in relative frame of reference, which rotates with constant angular velocity around axis of rotation. The governing equations are solved using finite vol?ume method applied on structured grids. The numerical procedure is based on the explicit multistage Runge-Kutta scheme that is coupled with modem numerical procedures for convergence acceleration. To demonstrate the accuracy of the described numer?ical method developed software is applied to numerical analysis of flow through impeller of axial turbocompressor, and obtained results are compared with available experimental data.

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A Calculation Scheme for Three-Dimensional Viscous Incompressible Flows

Journal of Fluids Engineering ◽

10.1115/1.3242670 ◽

1987 ◽

Vol 109 (4) ◽

pp. 345-352 ◽

Cited By ~ 4

Author(s):

M. Reggio ◽

R. Camarero

Keyword(s):

Incompressible Flows ◽

Stokes Equations ◽

Three Dimensional ◽

Numerical Procedure ◽

Numerical Data ◽

Momentum Balance ◽

Navier Stokes ◽

Test Cases ◽

Pressure Gradients ◽

Navier Stokes Equations

A numerical procedure to solve three-dimensional incompressible flows in arbitrary shapes is presented. The conservative form of the primitive-variable formulation of the time-dependent Navier-Stokes equations written for a general curvilinear coordiante system is adopted. The numerical scheme is based on an overlapping grid combined with opposed differencing for mass and pressure gradients. The pressure and the velocity components are stored at the same location: the center of the computational cell which is used for both mass and the momentum balance. The resulting scheme is stable and no oscillations in the velocity or pressure fields are detected. The method is applied to test cases of ducting and the results are compared with experimental and numerical data.

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Application of Lifting-Surface Theory to the Prediction of Hydroelastic Response of Hydrofoil Boats

Journal of Ship Research ◽

10.5957/jsr.1968.12.4.286 ◽

1968 ◽

Vol 12 (04) ◽

pp. 286-301

Author(s):

C. J. Henry

Keyword(s):

Equations Of Motion ◽

Three Dimensional ◽

Numerical Procedure ◽

Mode Shapes ◽

Operator Technique ◽

Elastic Mode ◽

Surface Theory ◽

Lifting Surface ◽

Modes Of Vibration ◽

Elastic Modes

In this report a theoretical procedure is developed for the prediction of the dynamic response elastic or rigid body, of a hydrofoil-supported vehicle in the flying condition— to any prescribed transient or periodic disturbance. The procedure also yields the stability indices of the response, so that dynamic instabilities such as flutter can also be predicted. The unsteady hydrodynamic forces are introduced in the equations of motion for the elastic vehicle in terms of the indicia I pressure-response functions, which are de rived herein from lifting-surface theory. Thus, the predicted vehicle-response includes the effects of three-dimensional unsteady flow conditions at specified forward speed. The natural frequencies and elastic modes of vibration of the vehicle and foil system in the absence of hydrodynamic effects are presumed known. A numerical procedure is presented for the solution of the downwash integral equations relating the unknown indicial pressure distributions to the specified elastic-mode shapes. The procedure is based on use of the generalized-lift-operator technique together with the collocation method.

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