Abstract: A method of enhancing a geologic model of a subsurface region is provided. A bed topography of the subsurface region is obtained. The bed topography is defined by a plurality of cells with an elevation associated with each cell center. The bed topography is represented as a cell-centered piecewise constant representation based on the elevations associated with the cells. The bed topography is reconstructed to produce a spatially continuous surface. Flux and gravitation al force-related source terms are calculated based on the reconstructed bed topography. Fluxes are calculated between at least two of the cells. Fluid flow, deposition of sediments onto the bed, and/or erosion of sediments from the bed are predicted using the fluxes and gravitational force-related source terms. The predictions are inputted into the geologic model to predict characteristics of the subsurface region, and the predicted characteristics are outputted.

Abstract: A method for controlling a water level of a drum of a heat recovery steam generation system for a combined cycle power plant is provided. The method includes determining an optimum drum water level during start up operation of the heat recovery steam generation system based on a characteristic chart model. The characteristic chart model is generated based on a plurality of vapor pressures of the drum and a plurality of temperatures of drum metal at the time of the start up operation of the heat recovery steam generation system.

Abstract: The invention relates to a method for determining a vortex geometry change of rotor vortices which are formed on a rotor which comprises a plurality of rotor blades. A dynamic lift distribution on the rotor plane is determined as a function of a lift change, which is correlated with n-times the rotor rotation frequency, on the rotor blades, from which the associated induced vertical velocities on the rotor plane can then be determined. The vortex geometry change is then calculated as a function of these induced vertical velocities.

Abstract: Systems, methods, and computer readable mediums. A method includes receiving a three dimensional model for a simulation that includes a first material portion that extends between first and second material handling elements. The method includes simulating motion of the first and second material handling elements and simulating an interaction between the first material portion and the first and second material handling elements. The method includes maintaining a constraint between the first and second material handling elements according to the first material portion, dynamically updating the model and displaying the simulation, and storing the model. A method for fluid simulation is also discussed.

Abstract: A computer system and method are disclosed for automatically generating a vascular model of a blood vessel to support, for example, identification of mechanical factors corresponding to the blood vessel. The method includes interpolating data points corresponding to a contour of the blood vessel; generating a structural model representing three-dimensional structural characteristics of the blood vessel based on interpolated contours; generating a fluid model representing three-dimensional characteristics of fluid flow within the vessel; and generating a vascular model based on the structural model and the fluid model. The method may also include performing a mechanical analysis of the vascular model to identify a mechanical factor associated with the vessel, for example, a factor associated with a potential plaque rupture within the vessel. Embodiments of the invention are applicable to the diagnosis, assessment, or treatment of cardiovascular diseases.

Abstract: A method for modeling fluid depletion in a reservoir is disclosed. A map is divided into cells. For each of the cells a value is stored that is based at least in part on a physical characteristic of the cell. At least one cell that contains a depletion location is identified along with a depletion amount corresponding to that location. An amount of walkers associated with the depletion location is determined. For each walker, a plurality of steps are calculated with each step to an adjacent cell. Each walker starts in the cell containing the depletion location associated with that walker. The visits of all the walkers are recorded by cell. The fluid depletion of each cell is then assessed based at least in part on the number of walker visits for each cell.

Abstract: The present invention is a process for designing the internal cooling passages with these small scale features using a meshed solid model in a FEA program to perform the CFD analysis. Instead of modeling these small scale features (cooling holes, impingement holes, and turbulators) in the meshed FEA solid model, most of the small scale features are replaced by grid extraneous source terms in which the small scale feature is eliminated from the solid model and replaced with point source terms. The source terms can duplicate the effect of the feature within the analysis without requiring the complex analysis that such features would require in the analysis. Text files for each of the cooling holes, impingement holes and turbulators are inputted and then translated into grid extraneous source terms that include position, energy, and continuity. A conjugate CFD solver performs an analysis and produces new values for the thermal and boundary conditions.

Abstract: An architecture tangibly embodied on a computer readable medium, the architecture for creating a particle system to be used in a physical simulation, including: a plurality of particle generation modules, wherein a particle generation module generates particles in a particle system; a plurality of particle motion modules, wherein a particle motion module produces physical motion of particles in a particle system; a plurality of particle display modules, wherein a particle display module renders particles in a particle system; a plurality of target effect modules, wherein a target effect module modifies particles in a particle system to perform in a certain way when they collide with an object; and a plurality of particle data structures.

Abstract: A new constrained interpolation profile method, which is stable and accurate but requires less amount of computation, is provided. CIP is a high-order fluid advection solver that can reproduce rich details of fluids. It has third-order accuracy but its computation is performed over a compact stencil. A novel modification of the original CIP method that fixes all of the above problems without increasing the computational load or reducing the accuracy is provided. The proposed method brings significant improvements in both accuracy and speed.

Abstract: According to one embodiment, a rotary drill bit comprises a bit body with a bit rotational axis extending through the bit body; blades disposed outwardly from exterior portions of the bit body; and cutting elements disposed outwardly from exterior portions of each blade. At least one blade has a substantially arched configuration. Each blade comprises a leading surface and a trailing surface, where the leading surface is disposed on the side of the blade toward the direction of rotation of the rotary drill bit, and the trailing surface is disposed on the side of the blade opposite to the direction of rotation of the rotary drill bit. The rotary drill bit also comprises junk slots. Each junk slot is disposed between an adjacent leading surface and an adjacent trailing surface of associated blades.

Abstract: A method for operating an internal combustion engine (10), the internal combustion engine (10) having a feed line (14) for feeding an air mixture into the internal combustion engine (10), the feed line (14) having a first section (27) at a comparatively low pressure, a compressor (22) for compressing the air mixture fed in, and a second section (29) at a comparatively high pressure arranged in series in the feed direction, the internal combustion engine (10) having an exhaust line (12) for discharging exhaust gas from the internal combustion engine (10), the exhaust line (12) having a section (43) in which the exhaust gas is at a comparatively low pressure, and the internal combustion engine (10) having an exhaust gas recirculation system (50) which recirculates into the first section (27) of the air feed (14) at least part of the exhaust gas which flows through the section (43) of the exhaust line (12) at the comparatively low pressure, the recirculated part of the exhaust gas and fresh air fed in forming th

Abstract: One embodiment of the present invention sets forth a technique for computing two-way rigid body coupling in a two-dimensional height field simulation, such as a shallow water simulation. Coupling from a rigid body to a fluid is computed using fluid displacement of the body in each grid cell. The body is projected onto a simulation plane to determine which grid cells are covered by the body. Fluid displacement from the body is computed for each grid cell based on displacement within a corresponding vertical column of fluid. Fluid displacement is distributed to neighboring grid cells prior to a height field computation. Coupling from the fluid to the rigid body is computed by integrating forces imparted on the body by the fluid at each grid cell. The integrated forces are used to compute a new position for the body in a subsequent simulation time step.

Abstract: The present invention reduces the number of diagrams and the workload of management and the like, by aggregating spools of a common format, in plant design technology using a three-dimensional CAD system. Format specific data which is stored separately according to spool format is obtained by aggregating the respective spools in the internal data, which is generated by a data acquisition means, into respective common formats by a spool aggregation means.

Abstract: A computer-aided method suitable for assisting in the design of an aircraft by providing the values of dimensional variables, dependant of a predefined set of parameters, for the complete aircraft or an aircraft component, comprising the following steps: a) Defining a parametric space grid; b) Obtaining a suitable Reduced Order Model (ROM) model, particularly a Proper Orthogonal Decomposition (POD) model, for calculating said variables for whatever point over the parametric space through an iterative process. Computer Fluid Dynamics (CFD) is used to calculate said variables for an appropriately selected set of points over the parametric space, which are used to approximate, via ROM and ad hoc interpolation, the variables in any other point over the parametric space. The method minimizes the required number of CFD calculations (to minimize the computational cost, which dramatically depends on this number) for a given level of error.

Abstract: A method has been designed for storing drilling knowledge and experience in a highly structured fashion that permits the user to identify drilling cases that meet user-specified criteria and to retrieve the knowledge and experience relating to those cases. In this way the user is able to retrieve the knowledge and experience learned in cases that are analogous to one or more current cases they are studying.

Abstract: A filament assisted chemical vapor deposition (FACVD) system. The FACVD system includes a gas distribution assembly, heater filament assembly, and a flow plate that is disposed between the gas distribution assembly and the heater filament assembly. The heater filament assembly and the flow plate have a corresponding extent across a dimension of the reactor and are separated by different distances across that extent.

Abstract: A method of generating a model of a turbidity current in a fluid is disclosed. A first flow layer in the turbidity current is defined. The method successively defines at least one more flow layer in the turbidity current. Each successive flow layer includes the previously defined flow layer. A set of depth-averaged flow variables for each flow layer is defined. A model is developed that describes the turbidity current. The model uses fluid flow equations and the set of depth-averaged flow variables for each flow layer to predict fluid flow in each flow layer. The model is then output.

Abstract: A method for determining rock and fluid properties of a fluid-containing subsurface geological formation is provided. First, a low resolution model of the geological formation is initially created from a lumped average parameter estimation derived from at least fluid pressure transient data obtained along a linear wellbore that traverses the formation. Next, the model parameters are updated using grid-based parameter estimation in which the low resolution pressure transient data are combined with data from at least one of seismic data, formation logs, and basic geological structural information surrounding the linear wellbore. Depending on the data available, this process may be carried out in a sequential manner by obtaining and combining additional dynamic data at selected areas. Through this process, multiple realizations of the properties of the geological formation (within the geological structural model) may be created based from the pressure-data conditioned geostatistics i.e.

Abstract: A tank wash visualization method for planning a tank wash cycle with respect to a tank includes creating a CFD model of the tank system, applying a plurality of parameters to the model, validating the CFD model, including alternate geometries in the model, and based on the model, determining the minimum time needed to successfully clean all parts of the tank.

Abstract: Provided are a method of a hybrid approach to multiple fluid simulation using volume fractions for realizing computer graphics through analysis of the Navier-Stokes equations, which is executed via a computer and takes into account variable densities and variable viscosities resulting from N multiple fluids existing in multiple lattice cells, and a recording medium wherein a program of the method is recorded.

Abstract: The present invention is directed to simulating evaporation of a droplet of a fluid, and may be embodied in a system, method or a computer-readable medium encoded with instructions for a processor to carry out such simulation. The present invention solves equations, which may represent an approximation of evaporation of the droplet on a domain whose size is varying over time. The boundaries of saturation regions are tracked and updated over time, and the equations are iteratively solved with the new boundaries of the saturation regions.

Abstract: The invention is a method of modeling a hydrocarbon reservoir. A parameter value in a set of equations is adjusted so that the output of the equations accurately matches observed sediment erosion and deposition behavior for sediment sizes throughout a range of about 10 microns to about 10 centimeters. An initial condition of a sediment bed in the hydrocarbon reservoir is defined. The equations are applied to the initial condition, wherein outputs of the equations express how a fluid flow affects erosion and deposition of sediments at the initial condition. The initial condition is adjusted based on the equation outputs to create a subsequent sediment bed condition. The equations are re-applied to the subsequent sediment bed condition a pre-determined number of times. The subsequent sediment bed condition is re-adjusted after each re-application of the equations. The model of the hydrocarbon reservoir is created and outputted.

Abstract: A method and system for optimal model-based multivariable balancing for distributed hydronic networks based on global differential pressure/flow rate information. A simplified mathematical model of a hydronic system can be determined utilizing an analogy between hydronic systems and electrical circuits. Thereafter, unknown parameters can be identified utilizing the simplified mathematical model and a set of available measurements. Next, balancing valve settings can be calculated by reformulating the simplified mathematical model based on the parameterized model. The sum of pressure drops across selected balancing valves can be then minimized to achieve optimal economic performances of the system. The data can be collected and transferred to a central unit either by wireless communication or manually by reading the local measurement devices. Such a multivariable balancing approach provides a fast and accurate balancing of distributed hydronic heating systems based on a centralized and non-iterative approach.

Abstract: A method and apparatus is provided for determining concentration of components in a liquid hydrocarbon mixture including hydrocarbons and water flowing through an alkylation process. A fluid flow path conveys the liquid continuously from the alkylation process through a first instrument configured for measuring a property of the liquid mixture, and having responsivities to concentration of the components, which are independent of the concentration of the water. A temperature detector generates temperature data for the liquid, and a second instrument measures another property of the liquid mixture. The instruments have mutually distinct responsivities to concentrations of the components.

Abstract: A forming process of plastic parts is simulated. The position and time of plastics particles which exceed at least one defined critical limit are detected. The final positions of particles in the surface layer of the plastics part are computed. The positions of the particles in the surface layer are defined as positions with deviations in the surface appearance.

Abstract: A computer implemented method for simulating a final pattern of a droplet of a fluid having a plurality of fluid properties is disclosed. The method includes using lubrication equations to represent solute flow, diffusion and evaporation of a droplet on a substrate. The method further includes solving the lubrication equations through temporal discretization and spatial discretization; and deriving the final pattern of the droplet from results of the solving. The final pattern is stored on a computer readable medium.

Abstract: Method for forming a fixed geometric grid for a fluid dynamics system multi-cell computer model, the system having one or more surfaces, includes representing the system surfaces by an array of contiguous polygons. The method also includes creating a single model cell that encompasses the entire system and assigning all the surface polygons to the single model cell. The method further includes subdividing at least the portion of the single model cell encompassing the surface polygon array, including subdividing all intersected assigned polygons, using one or more subdividing planes. The method still further includes reassigning the surface polygons to respective subdivided cells resulting from the subdividing step, identifying those subdivided cells having two or more surface polygons from a common system surface, and calculating effective common boundary areas and normal vectors for those cells. The method also includes treating “split” cells and “sliver” cells.

Abstract: A computer-implemented system for designing a pressure-dosed drain field comprising: a screen that allows a user to specify length and diameter for pipes that comprise the forcemain and discharge assembly, specify the pumping liquid level and discharge elevation, select the number of laterals and enter a specified residual pressure, enter or select a coefficient to be used in calculating friction losses, and enter the diameter and length of each manifold segment; a minor loss screen that calculates minor losses based on fitting selections made by the user; a pump file; a tabulated results screen; a gauge screen; and system and pump curves. A computer-implemented method of using the above system to design a pressure-dosed drain field. The purpose of the system and method is to enable an engineer to design a pressure-dosed drain field that will meet regulatory requirements for the system flow differential.

Abstract: The space including a particle system is discretized into volume elements. Signed distance values at each time and velocity values at a time are assigned to volume elements based on the particle system. The each volume element's position at the current time is extrapolated to an additional position at each additional time based on its respective velocity value. A temporally coherent signed distance value for each volume element is determined from its signed distance value and the signed distance values at the associated additional position at each additional time. A surface extracted from the temporally coherent signed distance values will be temporally coherent over the interval including the current time and the one or more additional times. Arbitrary surface properties may also be associated with volume elements and temporally coherent surface property values may be determined for each volume element using its respective velocity value in a similar manner.

Abstract: The invention relates to a real-world simulation device suitable for being installed in a computer designed to support a multitask programming environment (23). The device comprises a simulation manager (30), capable of working in asynchronous chaotic mode by repetitive sequences (31) on distinct simulation elements (40-70). Each simulation element works with at least one space/time datum, termed the structure point. A space/time datum includes a property datum, defining a current state of the structure point, and designates a function, applicable for modifying this current state. Said simulation manager (30) comprises two coupled simulation sections, namely a first and a second section, that are designed to simulate respectively a fluid medium and a solid body in the presence of said fluid medium.

Abstract: Using a level set projection method improves simulation of particulate fluid flow. The level set values are used to identify the particle-fluid boundary. The level set function is also used to evaluate the particle linear and angular momenta for the rigid particle projection. Governing fluid equations are solved in the solution domain, including in the region occupied by the rigid solid particle. The obtained velocity is rendered incompressible in the solution domain by doing the projection. The incompressible velocity field in the region occupied by the particle is further corrected to represent rigid body motion. This technique is further extended to embrace a particle collision scheme in a particulate fluid flow simulation.

Abstract: Embodiments of the present invention provide a finite difference method, a finite element projection, and a non-finite-element implementation of the finite element projection for solving the incompressible continuity equation on quadrilateral grids to obtain pressure and fluid velocity. An exemplary apparatus for simulating and analyzing the flow of an incompressible fluid is also provided. More particularly, embodiments of the present invention provide a non-finite-element-method (non-FEM) to implement the finite element projection to obtain a linear system whose coefficient matrix has an average bandwidth of five, in comparison to the finite difference scheme using conventional finite element projection and implementation with a bandwidth of nine. A two-dimensional-five-point-stencil-based non-FEM discretization is formulated to enforce the incompressible continuity equation.

Abstract: A computer-implemented inversion method for determining characteristics of a bottom roughness field using a numerical wave model is provided. Measured wave heights over an area of interest are compared to predicted wave heights calculated by a wave model using an estimated bottom roughness parameter. If the error between the measured wave heights and the predicted wave heights is within a specified tolerance level, the analysis ends and the value of the bottom roughness parameter used in the wave model is retrieved. If the error is not within the specified tolerance level, an Influence Matrix IM is used to obtain a revised estimated bottom roughness parameter. The wave model is re-run using the revised roughness parameter and the resulting predicted wave heights are compared to the measured wave heights. The inversion continues until the wave height error is within the specified tolerance level. When the inversion ends, the bottom roughness field that produced those predicted wave heights is retrieved.

Abstract: A finite difference level set projection algorithm on multi-staged quadrilateral grids for simulation of a split liquid film between two rollers. From one stage to the next, the number of meshes in the vertical direction changes by a select factor to provide a good balance between resolution and number of meshes. Having fewer meshes at the nip (the smallest gap between the rollers), the multi-staged quadrilateral grid allows a much bigger time step and requires much less CPU time to reach the steady state.

Abstract: The present invention is directed to simulating a droplet of a fluid, and may be embodied in a system, method or a computer-readable medium encoded with instructions for a processor to carry out such simulation. The present invention may evaluate differential equations, which may represent an approximation of behavior over time of the droplet on a non-flat substrate. The behavior that the differential equations represent may include diffusion in the droplet and evaporation of the droplet.

Abstract: An exemplary embodiment providing one or more improvements includes software which is robust, efficient, and has a very fast run time for user directed grid enrichment and flow solution adaptive grid refinement. All user selectable options (e.g., the choice of functions, the choice of thresholds, etc.), other than a pre-marked cell list, can be entered on the command line. The ease of application is an asset for flow physics research and preliminary design CFD analysis where fast grid modification is often needed to deal with unanticipated development of flow details.

Abstract: A software application implementable on a computer system is used to create a model of a hydraulic system to perform calculations. The user visually constructs a two-dimensional (2-D) connectivity model in the computer system. The 2-D connectivity model has a plurality of node points defined at various elements (sources, outlets, equipment, and junctions) of the hydraulic system and has segments interconnecting the node points. The user visually constructs a three-dimensional (3-D) segment model for each segment so that each segment model has the 3-D layout of the piping and the fittings for the segment. A 3-D system model of the entire hydraulic system is visually created in the computer system by combining the 3-D segment models. The software application performs calculations using the 3-D system model, and the 3-D system model can be visually or automatically verified to determine whether the model substantially corresponds to the 3-D layout of the hydraulic system, and has been laid out without errors.

Abstract: An apparatus includes a parallel computation unit including an input port and an output port and a one-dimensional computational fluid dynamics model. The input port is configured to sample at a time t1 a boundary condition signal for the one-dimensional computational fluid dynamics model and the output port is configured to provide an output signal before the boundary condition signal is sampled at a time t2.

Abstract: A computer-aided method suitable for assisting in the design of an aircraft by providing the dimensioning aerodynamic forces and other relevant values comprising the following steps: a) Selecting a set of parameters of the aircraft, being said aerodynamic forces and other relevant values dependant of said parameters; b) Performing flow field CFD RANS computations for a number N1 of different combination of values of said parameters; c) Obtaining said aerodynamic forces and other relevant values for whatever combination of values of said parameters through a reduced-order model, generated by computing the POD modes of the flow variables, expanding the flow variables using said POD modes and obtaining the POD coefficients of said expanded flow variables using a genetic algorithm that minimizes the error associated to the expansion of the Navier-Stokes equations. The invention also refers to a system for carrying out said method.

Abstract: A method of estimating a thermophysical property of a fluid using a local model is disclosed herein. The method includes generating, for use within the local model, a series expansion of thermodynamic equations relating to the thermophysical property and one or more derivatives involving the thermophysical property. The method further includes evaluating, based upon a set of specified values of parameters of the fluid, a first order term of the series expansion and a second order term of the series expansion. The values of the first order term and the second order term are then compared. A value of the thermophysical property is then automatically updated when the values of the first order term and the second order term are found to differ by more than a predefined amount.

Abstract: Methods and systems to reduce or eliminate numerical oscillations in solutions that occur when using conventional MPFA when modeling flow in a reservoir are provided. The technique may be referred to as enriched multi-point flux approximation (EMPFA) and may be used to improve the consistency and accuracy in constructing pressure interpolations in cells for the purpose of determining flux equations used in predicting flow in a reservoir.

Abstract: Realistic sprays for simulated fluids are created by adding a set of spray particles to a boundary region just below the fluid surface. The fluid surface is determined by solving a level set equation for a zero level corresponding to the fluid surface. Additionally, the boundary region is determined by solving the level set equation for a non-zero level corresponding to a surface at the specified depth from the fluid surface. The set of spray particles inherit an initial state, for example a velocity, from the fluid simulation. Subsequent motion of the spray particles is determined according to a ballistic simulation, rather than a fluid simulation, thereby substantially reducing the computational burden required to animate the fluid. Spray particles that sink below a specified depth from the fluid surface are removed.

Abstract: The invention provides an apparatus and methods for performing process simulation and structural analysis using a hybrid model. For example, a method of the invention automatically defines a hybrid solution domain by dividing a representation of a plastic component or mold cavity into two portions—a portion in which a simplified analysis may be conducted, and a portion in which a more complex analysis is required. The method may use as input any form of CAD data that describes the surface of a component or mold. Furthermore, the invention provides methods for simulating fluid flow within a mold cavity by automatically creating a hybrid solution domain, automatically discretizing the domain, and solving for the distribution of process variables within the solution domain.

Abstract: A method is provided for facilitating installation of one or more electronics racks within a data center. The method includes: placing a plurality of thermal simulators in the data center in a data center layout to establish a thermally simulated data center, each thermal simulator simulating at least one of airflow intake or heated airflow exhaust of a respective electronics rack of a plurality of electronics racks to be installed in the data center; monitoring temperature within the thermally simulated data center at multiple locations, and verifying the data center layout if measured temperatures are within respective acceptable temperature ranges for the data center when containing the plurality of electronics racks; and establishing the plurality of electronics racks within the data center using the verified data center layout, the establishing including at least one of reconfiguring or replacing each thermal simulator with a respective electronics rack.

Abstract: A method for determining absorbent article effectiveness of a virtual absorbent article. The steps of the method include providing a virtual body model, providing a virtual absorbent article model, providing virtual simulation software, running a virtual simulation of deformation of the virtual absorbent article model in proximity with the virtual body model, running a virtual simulation of the fluid balance of the virtual absorbent article model in proximity with the virtual body model, coupling the virtual simulation of deformation of the virtual absorbent article model and the virtual simulation of the fluid balance of the virtual absorbent article model, and determining absorbent article effectiveness of the virtual absorbent article model in proximity with the virtual body model.

Abstract: A gray-box model of a system is constructed by specifying constraints for the system and applying subspace system identification to inputs and outputs of the system to determine system matrices and system state sequences for the system. A transformation matrix that satisfy the constraints from the system matrices and the system state sequences is determined, wherein the transformation matrix defines parameters of the gray-box model.

Abstract: Provided is a method of simulating various viscoelastic fluids having viscosity, elasticity, and plasticity, based on smoothed particle hydrodynamics (SPH), which is widely used in fluid simulation using particles. Artificial forces related with viscosity, elasticity, and plasticity are added to address fundamental numerical limitations of a SPH method due to use of particle approximation and to improve expression of characterized motions of a viscoelastic fluid. Since the artificial forces are added, and parameters are adjusted according to the adding of the artificial forces, a fluid can be realistically expressed, and the control of a fluid motion is facilitated.

Abstract: Systems and methods for representing a surface with faces. Defining a face with inner and outer concave constraint lines. Representing the face with five initial vertices spread equidistant on each of the inner and outer concave constraint lines. Using a triangulation refinement method to transform the initial set of vertices into a first set of representative vertices.

Abstract: A system for measuring the superposition of a plurality of sound waves propagating within a conduit containing a fluid having a plurality of transducers positioned substantially parallel to the flow direction along the external surface of the conduit. The system includes means for modeling the superposition of a plurality of sound waves as they propagate within the conduit.

Abstract: An inundation simulation program and device using the same for displaying a map, receiving input from a user indicating a starting point and an ending point in a bank breakage section on the map, and displaying on the map a line connecting the starting point and the ending point. Further, the computer program and device calculates a direction of a flow quantity in the bank breakage section by calculating a normal line to the side of the inside area of the bank at the input band breakage section and making the bank breakage section discrete in the calculation grids of the inundation simulation.