In this paper, functioning of the internal combustion engine is studied in detail, with the effects of its speed and the sort of mixture strength over the heat transfer phenomenon of this direct injection hydrogen fuelled engine. This phenomenon is the most important one in the working of this engine. To study this mechanism, a model of this engine was designed keeping in view all the necessary aspects of the engine that take part in carrying out this function, in this model modified wall function was also used to make the working of it better and later on the model was discretized with the help of a structured hexahedron mesh. This model was tested with number of experiments and the governing equations showing the phenomenon of heat transfer and the physical activities of the engine going along were solved numerically. In this model, speed of the engine and equivalence ratio on the trends of the heat transfer were studied via keeping in view heat release rate, instantaneous rate of heat loss and heat transfer coefficient. This showed that the amount of heat transfer was increased up to 35 to 50 percent with the increase in equivalence ratio keeping its functioning into a normal range. The increase in the heat transfer is obtained when the overall engine's speed is increased. These parameters ultimately may help in determining the new correlation. © Sila Science.