In this work, we report on the development of a time-averaged Eulerian multiphase approach applied in the wall boiling process especially in the forced convective boiling process. Recently, in order to obtain accurate bubble dynamics and reduce case dependency, a single bubble model for nucleate boiling based on known published models was developed. The model considers geometry change and dynamic contact and inclination angles during bubble growth. The model has good agreement with experiments. However, the predicted bubble dynamics is dependent on the wall superheat (cavity activation temperature). This single bubble model requires an update of the current nucleation site activation and heat flux partitioning models in time-averaged Eulerian multiphase approaches. In this work, we will introduce this implementation in detail. Further, with help of the MUSIG (MUltiple SIze Group) model and a breakup and coalescence model, the time-averaged Eulerian approach could simulate the bubble size distribution in a heated pipe. With the necessary calibration of the nucleation site density, the comparisons between the calculation results and Bartolomei et al.’s experiments demonstrate the success of the implementation and the accuracy of this approach.