We survey the problem solving carried out in the textbooks of the fundamental fluid dynamics. The initial problem solving method that is usually called as an expert system was based on the if-then rules. This method likely represent that the problems to be solved are very limited and the application is not wide enough. In order to overcome this defect, an ontological based approach is proposed. In this method, the well structured knowledge based is designed to clarify the relations among pieces of knowledge. Then the problems are attempted to solve by using the principle and naive knowledge that we have. In this paper, we present an overview of the representation of the knowledge and solving process. We first show how we follow the solving process of the problem in basic fluid engineering, and then represent the formal hierarchy structure is required to solve the problem that is not limited to a narrow application area.
