The present work deals with the development of a compressible phase-change solver and implementation toward the numerical modeling and investigation of a part-unit cell of a pulsating heat pipe (PHP). The fundamental understanding of the working of the part-unit cell is imperative in the development of a complete Computational Fluid Dynamics (CFD) model of a PHP. The compressible model developed in the present work is based on the Volume-of-Fluid solver of the open source CFD software, OpenFOAM, in which the contour-based interface reconstruction algorithm and the contact-line evaporation model have been incorporated. Owing to the lack of a single standard benchmark validation case for a compressible phase-change solver, a huge emphasis in the present work is laid on the solver development and validation, the latter part of which is conducted in stages. Furthermore, simulations for the formation of a Taylor-Bubble through a constrained bubble growth are performed and the fallacy of an incompressible solver is shown distinctly. The validated solver is used to model a part-unit cell of a PHP and a parametric study is performed on the part-unit cell. The effect of variation of evaporator length, evaporator superheat, and liquid fill ratio on the performance of the PHP is discussed. © 2016 Taylor & Francis.