Mobility model is a crucial feature to differentiate ad hoc networks from other networks. The evaluation of dynamic network properties caused by mobility model is the basic problem for research on protocol simulation and related technologies, such as topology control and network performance measurement, in ad hoc networks. In this paper, a model-based description of ad hoc networks is improved to avoid the drawbacks in describing the corresponding space-time dynamic properties. Then a universal evaluation method with measureable space-time dynamic properties is presented. The dynamic properties of several mobility models are studied by constructing the space distribution of the nodes and designing the models for analyzing the topological space-time dynamic properties. Furthermore, a novel mobility model based on circular curve movement is proposed to improve the flexibility and the capability to describe realistic scenarios with curve movement. Simulation with NS2 shows the presented method can effectively evaluate the characteristics of the existing mobility models. The numerical results also show that the proposed mobility model has good dynamic properties in comparison with the existing mobility models.