In this paper, we propose a new algorithm for introducing Coarray Fortran (CAF) into a program that dynamically analyzes the frequency domain in soil–structure interactions. This was implemented in ...KIESSI-3D, which is frequency domain soil-structure interaction analysis computer code based on finite and infinite element techniques, and the performance of analysis speed based on the number of images (or coarrays) and cores per image was evaluated. For the performance evaluation, we used examples of full-scale nuclear power plant buildings with a shallow foundation model as well as a deep foundation model. In terms of analysis speed, the new KIESSI-3D improved the analysis speed by an average of 2.78 times for the shallow foundation problem and 2.69 times for the deep foundation problem, compared with the existing KIESSI-3D, because of the new algorithm and CAF. Further, as the number of cores and the internal memory size in the computer systems increased, the efficiency of also parallel processing increased.
An efficient joint two-dimensional direct current resistivity (DCR) and magnetotelluric (MT) inversion, referred to as WSJointInv2D-MT-DCR, was developed with FORTRAN 95 based on the data space ...Occam's inversion algorithm. Our joint inversion software can be used to invert just the MT data or the DCR data, or invert both data sets simultaneously to get the electrical resistivity structures. Since both MT and DCR surveys yield the same resistivity structures, the two data types enhance each other leading to a better interpretation. Two synthetic and a real field survey are used here to demonstrate that the joint DCR and MT surveys can help constrain each other to reduce the ambiguities occurring when inverting the DCR or MT alone. The DCR data increases the lateral resolution of the near surface structures while the MT data reveals the deeper structures. When the MT apparent resistivity suffers from the static shift, the DCR apparent resistivity can serve as a replacement for the estimation of the static shift factor using the joint inversion. In addition, we also used these examples to show the efficiency of our joint inversion code. With the availability of our new joint inversion software, we expect the number of joint DCR and MT surveys to increase in the future.
•Joint inversion software for 2D magnetotelluric and direct current resistivity.•Both data help enhance each other reducing the ambiguities of the interpretation.•The software is free for academic uses.
The EQuivalent Polynomials library, EQP, herein provided is a powerful tool for the numerical integration, with classical quadrature rules (e.g. Gauss–Legendre), of a function given by the product of ...an arbitrary polynomial times a Heaviside step function. The library can handle a multiplicity of shapes for the integration domain in one, two and three dimensions. Originally developed by Ventura (Ventura, 2006) to overcome the long-standing problem of integrating discontinuous functions in the context of the eXtended Finite Element Method, EQP library has been recently generalized to meet the needs of very different fields, spanning from computational mechanics, to computer graphics, evaluation of geometric region (mass) properties and computer simulation in general.
A new method of adaptive movement control of guide and conical rolls is proposed in three-dimension finite element (3D FE) simulation of ring rolling. The movement mathematical models of guide and ...conical rolls are established with combining with the node track method in an FE model. By means of the user subroutine VUAMP interface of ABAQUS, an adaptive roll motion subroutine is written by FORTRAN software, which carried out the adaptive movement control of guide and conical rolls. The simulation results show that the ring can always keep a good circular degree and ensure final deformation quality in ring rolling process. The effectiveness of FE simulation has been verified by practical experiments. It overcomes some shortcomings of the traditional method, such as the large amount of computation, low universality, ubiquitous error, time consuming, and lack of universality and so on. And, it guarantees the balance of ring rolling and the roundness of the rolled ring.
The dual-axis buckling of Laminated composite skew hyperbolic paraboloid with cutouts subjected to the in-plane biaxial and the shear load is investigated for various boundary conditions using the ...present mathematical model. Variation of transverse shear stresses is represented by a second-order function across the thickness, and the cross-curvature effect is also included via strain relations. The transverse shear stress-free condition at the shell top and bottom surfaces is also satisfied. This mathematical model (having a realistic second-order distribution of transverse shear strains across the thickness of shell) requires unknown parameters only at the reference plane. For generality in the present analysis, nine-node curved isoparametric element is used. So far, no solution exists in the literature for dual-axis buckling problem of laminated composite skew hyperbolic paraboloids with cutouts. As no result is available for the present problem, the present model is compared with suitable published results and then it is extended to analyze biaxial and shear buckling of laminated composite skew hyperbolic paraboloids. A C
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finite element coding in FORTRAN is developed to generate many new results for different boundary conditions, skew angles, lamination schemes, etc.
This paper presents a CFD modelling of hydrodynamics and heat transfer for scaling up the gas-solid jetting fluidized beds. Through coupling with energy conservation equation, a simple hydrodynamic ...model (Brandani and Zhang, 2006) is extended to predict the heat transfer between the gas and particle phases in a fluidized bed. A similitude method is established by nondimensionalizing the governing equations involved in the CFD model for fluidized beds. Numerical simulations are conducted in the platform of CFX 4.4, a commercial CFD code, together with user-defined FORTRAN subroutines. The controlling equations are verified in the fluidized bed with a pulse jet by using the penetration theory (Kuipers et al., 1992). The effect of jet on heat transfer is examined by introducing a continuous jet. The computational results show that local time-averaged heat transfer coefficient increases with an increase in solid thermal conductivity or with a decrease in jet gas velocity, particle size and nozzle size. Reasonable similarities of jet evolution, time-averaged radial voidage distribution and dimensionless heat transfer coefficient can be obtained in the standard, two-sized and five-sized fluidized beds when dimensionless parameters are matched.
Dimensionless jet depths and heat transfer coefficient in multi-sized fluidized beds. Display omitted
•A CFD model is suggested to predict hydrodynamics and heat transfer in fluidized beds.•The model is verified by using a pulse jet gas and the penetration theory.•Effect of jet on heat transfer is examined by introducing a continuous jet.•A similitude method is established by nondimensionalizing governing equations.•Effect of jet on scaling rule is predicted in the standard and enlarged beds.
Water-flow window combines the functions of transparent building envelop, solar collector, as well as sun shading. Coloured particles are added to the flowing water within window cavity in order to ...provide extra shading, prevent indoor glare and enhance solar collection. The energy consumption of both air-conditioning system and water heating device can be further reduced. The aim of present investigation is to predict and analyze the year-round energy performance of a well-insulated water-flow window with different shading control modes. Accordingly, physical model of water-flow window is built up. FORTRAN program is developed and utilized in the numerical simulation.
Results show that water-flow window can achieve exceptional sun blocking and cooling load reduction without occupying extra space. The year-round solar energy collection efficiency is within the range of 17.95∼21.06%. At the same time, indoor heat gain through the window can be reduced by around 50% compared with common double-layer window. The water-flow window under discussion has great application potential in buildings with constant hot water demand and high-density air-conditioning cooling load. In practice, the shading control mode should be carefully decided, and factors including climate region, hot water demand, window size and occupants' preference on indoor light environment should be taken into consideration. Numerical simulation proves to be an efficient method in predicting the energy performance of similar innovative-designed windows and a good assist in decision-making of real projects.
As Automatic Differentiation (AD) usage is spreading to larger and more sophisticated applications, problems arise for codes that use several programming languages. This work describes the issues ...involved in interoperability between languages and focuses on the main issue which is parameter-passing. It describes the architecture of a source-transformation AD tool and the algorithms used to differentiate mixed-language codes. A language-independent internal representation enables the application of global analysis and strategies on the entire source code. Our goal is that the Tapenade AD tool differentiates codes that mix C and Fortran and generates efficient differentiated code using these strategies.
Ship collisions are rare events that may have a significant impact on the safety of people, ships, and other marine structures, as well as on the environment. Because of this, they are extensively ...studied but events that just precede collision are often overlooked. To rationally assess collision risks and consequences, a ship’s trajectory, and consequently the velocity and collision angle, should be known. One way to achieve this is through accurate modelling of ship manoeuvrability in collision analysis using non-linear FEM (NFEM). The Abkowitz manoeuvring model is implemented in the LS-Dyna software code and is therefore coupled with FEM calculations. Hydrodynamic forces are calculated in each time step of the LS-Dyna calculation and added to the FE model continuously through calculation. The accuracy of the calculations depends on the choice of and values of hydrodynamic derivatives from the Abkowitz model. Abkowitz’s model derives hydrodynamic forces in the Taylor expansion series to provide hydrodynamic derivatives. The application of the procedure is sensitive on higher-order Taylor series members. This article reviews different sets of hydrodynamic derivatives available for the KVLCC2 ship. Each of them is incorporated into the LS-Dyna NFEM solver by a user-made Fortran subroutine, with standard Zigzag and turning manoeuvres simulated and results compared with the experimental tests. As a result, the optimal selection of hydrodynamic derivatives is determined, laying a foundation for assessing the risk of ship collision due to different ship manoeuvres prior to the collision itself.
Differences in the simulation of hydrologic processes by watershed models directly affect the accuracy of results. Surface runoff generation can be simulated as either: (1) infiltration-excess (or ...Hortonian) overland flow, or (2) saturation-excess overland flow. This study compared the Hydrological Simulation Program—FORTRAN (HSPF) and the Soil Moisture Routing (SMR) models, each representing one of these mechanisms. These two models were applied to a 102 km
2 watershed in the upper part of the Irondequoit Creek basin in central New York State over a seven-year simulation period. The models differed in both the complexity of simulating snowmelt and baseflow processes as well as the detail in which the geographic information was preserved by each model.
Despite their differences in structure and representation of hydrologic processes, the two models simulated streamflow with almost equal accuracy. Since streamflow is an integral response and depends mainly on the watershed water balance, this was not unexpected. Model efficiency values for the seven-year simulation period were 0.67 and 0.65 for SMR and HSPF, respectively. HSPF simulated winter streamflow slightly better than SMR as a result of its complex snowmelt routine, whereas SMR simulated summer flows better than HSPF as a result of its runoff and baseflow processes.
An important difference between model results was the ability to predict the spatial distribution of soil moisture content. HSPF aggregates soil moisture content, which is generally related to a specific pervious land unit across the entire watershed, whereas SMR predictions of moisture content distribution are geographically specific and matched field observations reasonably well. Important is that the saturated area was predicted well by SMR and confirmed the validity of using saturation-excess mechanisms for this hillslope dominated watershed.
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