  The Weakly-Compressible Smoothed Particle Hydrodynamics (WCSPH) method is a
Lagrangian method that is typically used for the simulation of incompressible
fluids. While developing an SPH-based scheme or solver, researchers often
verify their code with exact solutions, solutions from other numerical
techniques, or experimental data. This typically requires a significant amount
of computational effort and does not test the full capabilities of the solver.
Furthermore, often this does not yield insights on the convergence of the
solver. In this paper we introduce the method of manufactured solutions (MMS)
to comprehensively test a WCSPH-based solver in a robust and efficient manner.
The MMS is well established in the context of mesh-based numerical solvers. We
show how the method can be applied in the context of Lagrangian WCSPH solvers
to test the convergence and accuracy of the solver in two and three dimensions,
systematically identify any problems with the solver, and test the boundary
conditions in an efficient way. We demonstrate this for both a traditional
WCSPH scheme as well as for some recently proposed second order convergent
WCSPH schemes. Our code is open source and the results of the manuscript are
reproducible.
