Radiation hydrodynamics modelling of kilonovae with <tt>SNEC</tt>

We develop a method to compute synthetic kilonova light curves that combines numerical relativity simulations of neutron star mergers and the $\texttt{SNEC}$ radiation-hydrodynamics code. describe our implementation initial boundary conditions, r-process heating, opacities for simulations. validate approach by carefully checking energy conservation is satisfied comparing results with those two semi-analytic curve models. apply code calculation color three binaries having different mass ratios (equal unequal mass) merger outcome (short-lived long-lived remnants). study sensitivity hydrodynamic effects, nuclear physics uncertainties in heating rates, duration find hydrodynamics effects are typically negligible homologous expansion good approximation most cases. However, pressure forces can amplify impact radioactive rates. also shocks possibly launched into outflows relativistic jet. None models match AT2017gfo, GW170817. This points possible deficiencies which neglect non-LTE additional injection from remnant, need go beyond assumption spherical symmetry adopted this work.