中文摘要：

提出了一种新型基于气流绕钝头球体速度模型的大气参数估计方法,主要解决大气参数中的攻角、侧滑角、自由流速度的求解问题。首先,根据势流模型推导了可压缩流下的速度模型,利用气体热力学公式和可压缩性系数对模型进行了校正。其次,通过传感器策略组合,根据修正的模型推导了基于气流速度值求解大气参数的公式。最后,利用Fluent软件仿真并采样了气流绕钝头球体速度分布情况,通过仿真数据验证了各公式的有效性,表明基于气流速度值的大气参数估计方法是可行的。该方法能够实现较大的攻角和速度的测量并且明显提高大气参数估计的实时性。

英文摘要：

Traditional FADS is based on pressure sensor to measure the atmospheric parameters,and has been wide used in modern advanced aircraft.However,the lag of aerodynamic model and the complex iteration of the nonlinear equation may lead to the poor real-time characteristic and the instability of the system.An new method measuring the atmospheric parameters based on acoustic vector sensor is proposed,the airflow velocity is measured instead of the pressure.A modified airflow velocity distribution model over a blunt sphere is built based on uncompressible potential flow,which relates the airflow velocity to atmospheric parameters.The thermodynamic functions and a compression coefficient are used to calibrate the model.The formulations of atmospheric parameters,angle of attack,angle of sideslip and free stream velocity are derived from sampled velocity obtained by three strategically selected sensors＇.The correct angle of attack is chosen from two different solutions.The distribution of airflow velocity over blunt sphere is simulated by Fluent,and the simulation data verifies the validity of these formulations,so the estimation of atmospheric parameters based on flow velocity is feasible.Further more,this method can be used at high angle of attack and greatly improve the system real-time.