Leak detection has been an important aspect of pipeline operation and management，and real-time simulation has become one of the mostly adopted approaches.The quasi-steady hypothesis commonly adopted in pipeline transient model has the drawback of under-estimating the transient energy loss which will cause relatively big errors between the calculated and measured values.In this paper the recent results on the topic of energy loss was reviewed and its impact on the simulation results was studied based on the data collected from real pipelines.Real-time simulation results showed that the outputs of the unsteady wall shear stress model and leak detection based on this model had higher precision.