Local Well-Posedness of the Capillary-Gravity Water Waves with Acute Contact Angles

We consider the two-dimensional capillary-gravity water waves problem where the free surface \(\Gamma _t\) intersects the bottom \(\Gamma _b\) at two contact points. In our previous works (Ming and Wang in SIAM J Math Anal 52(5):4861–4899; Commun Pure Appl Math 74(2), 225–285, 2021), the local well-posedness for this problem has been proved with the contact angles less than \(\pi /16\). In this paper, we study the case where the contact angles belong to \((0, \pi /2)\). It involves much worse singularities generated from corresponding elliptic systems, which have this strong influence on the regularities for the free surface and the velocity field. Combining the theory of singularity decompositions for elliptic problems with the structure of the water waves system, we obtain a priori energy estimates. Based on these estimates, we also prove the local well-posedness of the solutions in a geometric formulation.