Hydrogen energy is one of the most promising candidates for clean and renewable energy in the coming future. Under the commission of safety study in hydrogen application, storage and transportation, CFD code analysis is always an important component in the engineering design workflow. Among the three stages of CFD analysis, the solver part has been well studied in the past two decades. However, the pre-processing and post processing parts demand further study. The meshing process can be an important factor on the convergence speed and simulation reliability in hydrogen CFD study, which makes Cartesian mesh as an important choice in hydrogen safety codes However, traditional meshing process relies heavily on hand-based input card manipulation, which is inefficient and prone to human's improper manipulation. With the recent developments in codes like GASFLOW-MPI and FLACS, new functions have been added, which provide automatic mesh generation directly from the CAD geometry. In this work, the algorithm on automatic mesh generation will be further studied, which is more robust on the defective CAD geometries. In addition, application of the new evolving Virtual Reality technology will be implemented on the post-processing of the simulation result, which provides a better view in a real 3D environment. In the application part, three cases on a leaking hydrogen tank, a steam generator and a single car garage will be studied with regards to the validation of the new mesh generation approach. Finally, the Virtual Reality (VR) rendering performance will be studied based on the leaking hydrogen distribution in the single car garage. The work shows that the winding number based approach is an efficient and robust solution for the mesh generation of hydrogen CFD codes, and VR technology is a powerful tool for hydrogen safety simulation result rendering. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.