CAJ | 학술논문

文章针对目前模型试验只能获得各向同性湍流积分长度这一现状,建立了各向异性湍流积分长度数值预报方法:(1) RANS预报初始定常流场;(2) 大涡模拟计算脉动速度场;(3) 脉动速度相关函数计算各向同性湍流积分长度;(4) 计算各向异性湍流积分长度. 通过二维水翼模型试验验证了水中各向同性湍流积分长度的数值预报精度,平均误差6.81%;通过风洞螺旋桨验证了空气中各向异性湍流积分长度计算方法.对SUBOFF桨盘面处各向异性湍流积分长度的预报研究发现,各方向湍流积分长度外半径大于内半径;潜艇上部涡团扩散较下部明显,内半径湍流积分长度波峰随着角度增大而内移;Λ1|1、Λ1|2和Λ1|3周向分布受指挥台围壳和稳定翼马蹄涡影响,波峰出现在20°和90°左右;Λ3|1和Λ3|2的频率峰值受指挥台围壳和稳定翼马蹄涡脱落频率(约15 Hz)影响,峰值集中在30 Hz以下.该文提出的各向异性湍流积分长度预报方法,为下一步螺旋桨低频宽带噪声预报中构造新的湍流波数谱以提高预报精度提出了思路.
문장침대목전모형시험지능획득각향동성단류적분장도저일현상,건립료각향이성단류적분장도수치예보방법:(1) RANS예보초시정상류장;(2) 대와모의계산맥동속도장;(3) 맥동속도상관함수계산각향동성단류적분장도;(4) 계산각향이성단류적분장도. 통과이유수익모형시험험증료수중각향동성단류적분장도적수치예보정도,평균오차6.81%;통과풍동라선장험증료공기중각향이성단류적분장도계산방법.대SUBOFF장반면처각향이성단류적분장도적예보연구발현,각방향단류적분장도외반경대우내반경;잠정상부와단확산교하부명현,내반경단류적분장도파봉수착각도증대이내이;Λ1|1、Λ1|2화Λ1|3주향분포수지휘태위각화은정익마제와영향,파봉출현재20°화90°좌우;Λ3|1화Λ3|2적빈솔봉치수지휘태위각화은정익마제와탈락빈솔(약15 Hz)영향,봉치집중재30 Hz이하.해문제출적각향이성단류적분장도예보방법,위하일보라선장저빈관대조성예보중구조신적단류파수보이제고예보정도제출료사로.
This paper proposes a numerical method to predict the anisotropic turbulence integral length in view of this situation that the classic (isotropic) turbulence integral length is mainly acquired from experi-ments. Where RANS is utilized to predict the initial steady flow field; LES is used to calculate fluctuating velocity; the classic turbulence integral length is calculated based on cross-correlation function and the anisotropic turbulence integral length is finally predicted. The numerical method to predict isotropic turbu-lence integral length is validated the experimental data from 2-D hydrofoil, and the average error is 6.81%;and anisotropic turbulence integral length prediction method is validated by wind tunnel test. Then the anisotropic turbulence integral length of SUBOFF is studied and understood: the integral lengths at outside radius are lager then those at inside radius in all directions; the vortexes in the upper part diffuse more in-tensely than that in the under part, leading to the peak bars moving inside along with the angle increasing;the peak bars of Λ1 1,Λ1 2 and Λ1 3 are all near 20° and 90° according to the exists of horse-shoe vortex-es of conning tower and stabilizers;The peak frequency of Λ3 1 and Λ3 2 are both lower than 30 Hz as the shedding frequency of the horse-shoe vortexes is about 15 Hz. The current work lays the foundation of con-structing new turbulence spectrum to improve the accuracy of prediction of low-frequency broadband noise.