A diffuser surrounding a rotor is able to increase the power coefficient of a wind turbine above the Betz-Joukowsky limit (16/27), and so has attracted great attention for many years. This work presents a novel analysis of the performance of diffuser-augmented wind turbines (DAWTs) taking into account the influence of the diffuser efficiency and thrust, in which a new formulation for the far-wake velocity is proposed. The mathematical model extends Blade Element Theory to include the diffuser efficiency in the axial velocity formulation, which in turn, modifies the thrust and power. Additionally, a correction for high rotor thrust is presented, where a quadratic equation is used to incorporate the losses within the diffuser that are associated with the efficiency being less than 100%. An algorithm to assess DAWT performance was developed and implemented. The new model was validated by comparison with experimental data match and shows good agreement when a diffuser efficiency of 80% is assumed. The impact of the diffuser is assessed by the augmentation factor, the ratio of turbine efficiency to the Betz-Joukowsky limit. It is shown, for example, that the augmentation factor exceeds unity only for efficiency greater than 74% when the diffuser thrust is 0.2 of the total thrust and ratio of the rotor area to diffuser exit area is 0.54.

围绕转子的扩散器能够将风力涡轮机的功率系数提高到Betz-Joukowsky极限（16/27）以上，因此多年来引起了极大的关注。这项工作考虑了扩压器效率和推力的影响，对扩压器增强型风力涡轮机（DAWT）的性能进行了新颖的分析，提出了一种新的远流速度公式。该数学模型扩展了“叶片元件理论”，以将扩散器效率包括在轴向速度公式中，从而改变了推力和功率。另外，提出了一种针对高转子推力的校正方法，其中使用一个二次方程式将扩散器内的损耗与效率小于100％相关联。开发并实现了一种评估DAWT性能的算法。通过与实验数据匹配进行比较，验证了新模型，并在假设扩散器效率为80％时显示出良好的一致性。扩散器的影响通过增加系数，涡轮机效率与Betz-Joukowsky极限的比率进行评估。例如，示出了当扩压器推力为总推力的0.2且转子面积与扩压器出口面积之比为0.54时，仅当效率大于74％时，增大系数才超过1。