多喷管火箭起飞噪声环境预示方法  

Prediction method of lift-off acoustic environment for multinozzle rockets

作　　者：王浩轩 容易[2] 曾耀祥 WANG Haoxuan;RONG Yi;ZENG Yaoxiang(Beijing Institute of Astronautical Systems Engineering,Beijing 100076,China;China Academy of Launch Vehicle Technology,Beijing 100076,China)

机构地区：[1]北京宇航系统工程研究所,北京100076 [2]中国运载火箭技术研究院,北京100076

出　　处：《清华大学学报（自然科学版）》2024年第8期1357-1366,共10页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(U23B6009)。

摘　　要：为提高多喷管火箭起飞噪声环境预示能力,该文基于Kudryavtsev方法提出了3点修正:利用分布源方法(distributed source method, DSM)修正自由喷流段声源指向性,并重新分配噪声源功率;通过噪声遮蔽模型估计发射台和勤务塔的噪声衰减;采用芯级多喷流等效为单喷流计算和助推单喷流独立计算的方法预示多喷流噪声。利用修正方法预示了某火箭起飞不同时刻勤务塔附近噪声环境。对比修正方法和Kudryavtsev方法发现,修正方法在火箭起飞2 s内最大预示误差小于5.0 dB,预示精度相较Kudryavtsev方法提高约10.0 dB;修正方法能更准确预示声压级峰值时刻,且峰值时刻附近声压级误差小于3.0 dB;修正方法的1/3倍频程声压级谱全频段预示误差小于6.0 dB,关键频段预示误差小于3.0 dB。修正方法预示精度更高,具有重要工程应用价值。[Objective]Lift-off acoustic environment is most severe during the rocket flight.This broadband random noise can cause high-intensity random responses of the rocket structure.Predicting the lift-off acoustic environment is important to guide the design of rocket noise protection.The Kudryavtsev method is a comprehensive technique that considers five noise sources during lift-off of rocket;however,it weakens the directivity of the free jet and neglects the shielding of the launch pad and service tower.In addition,the multijet equivalent method does not consider the distance between jets.Therefore,three modifications are made based on the Kudryavtsev method to enhance the prediction ability of the lift-off acoustic environment of multinozzle rockets.[Methods]The lift-off acoustic environment was predicted using five types of noise sources,namely the noise of the undisturbed free jet above the launch table,noise of interaction between the jet and launch table,noise of reflection by the launch table,noise of the disturbed free jet between the launch pad entrance and deflector,and noise of diversion channel exit.For free-jet noise sources,the distributed source methodⅡ(DSM-Ⅱ)was employed to correct directivity and redistribute the noise power.Herein,two normalization curves of noise power distribution in DSM-Ⅱwere corrected by empirical formulas,increasing the results by about 1.5 dB.Subsequently,considering the structural shielding in noise propagation paths,Maekawa's noise shielding model was utilized to estimate the noise attenuation of the launch pad and service tower.Based on numerical simulation results,a equivalent method was used for predicting the multijet noise of rockets.The multijet noise of the core stage was calculated by a equivalent single jet,and the single jet noise of boosters was calculated independently.The modified method was employed for predicting the acoustic environment near the service tower of a certain rocket at different times of lift-off.[Results]Comparison results indicated that f

关 键 词：起飞噪声环境 指向性 噪声遮蔽 多喷管火箭 导流槽 

分 类 号：V475.1[航空宇航科学与技术—飞行器设计]