YAML schema for Chrono::SPH fluid simulation specification

A Chrono YAML SPH simulation file defines the parameters needed to run a Chrono::SPH simulation. It consists of three main objects:

• The Chrono version (chrono-version) that is compatible with the YAML model specification. This is a string of the form M.m (major.minor) or M.m.p (major-minor-patch), although only the two fileds are verified for compatibility.
• The fluid solver type, a string identifying supported CFD solvers.
• The simulation object that contains simulation methods, solver and integrator settings, and visualization options.

Simulation specification

YAML schema

The YAML model specification file must follow the data/yaml/schema/sph_simulation.schema.yaml provided in the Chrono data directory:

# =============================================================================
# PROJECT CHRONO - http://projectchrono.org
#
# Copyright (c) 2025 projectchrono.org
# All rights reserved.
#
# Use of this source code is governed by a BSD-style license that can be found
# in the LICENSE file at the top level of the distribution and at
# http://projectchrono.org/license-chrono.txt.
# =============================================================================
#
# Schema for a Chrono::SPH YAML fluid simulation specification file.
# The `chrono-version` must match the Chrono major and minor version numbers.
# The `simulation` object contains the schema for the simulation YAML specification.
#
# =============================================================================
 
required: [chrono-version, simulation]
 
chrono-version:
  type: string
  description: Chrono version compatible with this YAML simulation specification (M.m or M.m.p)
 
# -----------------------------------------------------------------------------
# Definitions of common Chrono types
 
vector3d: &VECTOR3D   # Specification of a ChVector3d
    type: array
    items:
        type: number
    minItems: 3
    maxItems: 3
 
# -----------------------------------------------------------------------------
# Definition of a Chrono::SPH simulation
 
simulation:
  description: |
    Schema for simulation parameters.
    This schema defines the SPH parameters, kernel, discretization, numerical integration, and visualization settings.
  type: object
  required: [time_step]
 
  properties:
  
    time_step:
      type: number
      description: Time step size in seconds.
      minimum: 0
    
    end_time:
      type: number
      description: |
        Total simulation duration in seconds.
        The simulation will run from t=0 to t=end_time. A negative value indicates na infinite end time.
      minimum: 0
      default: -1
    
    # TODO
 
    sph:
    kernel:
    discretization:
    boundary_conditions:
    integration:
    proximity_search:
    particle_shifting:
    viscosity:
    output:
    visualization: