温度分层环境中水下航行器机动下潜热尾流特征

Thermal wake characteristics of an underwater vehicle in a maneuvering diving mode in a temperature-stratified environment

为研究水下航行器热尾流引起的水面温度异常,本文采用有限体积法建立三维SUBOFF数学模型。使用Fluent UDF、Patch分别控制水下航行器机动下潜方式和水域温度分层。数值模拟结果表明:水下航行器在机动下潜时,热尾流在水面会形成由2条不连续高温热斑组成的椭圆形温度异常区,且正温度梯度分层水域会增强热尾流引起的水面温度异常。在无热排放条件下,水下航行器机动下潜会对水域温度分层发生较大扰动,从而出现冷尾迹。相反,受热排放影响,热尾流以肾形涡的形式向上浮升,涡结构尺度随着航行距离的增大而增大,核心温度随着航行距离的增大而减小。正温度梯度分层海水会增强冷却水引起的海面温度异常特征,且温度梯度越大,热斑越连续,热斑核心最高温度为292.24 K,与周围海水温度差值为0.12 K。

To study the surface temperature anomalies caused by an underwater vehicle wake,a three-dimensional SUBOFF mathematical model was established using the finite volume method.Fluent UDF and Patch were used to control the maneuvering diving mode and water temperature stratification,respectively.The numerical simulation results show that the wake forms an oval temperature anomaly region comprising two discontinuous high-temperature hot spots on the surface of the underwater vehicle maneuvering down,and a stratified water area with a positive temperature gradient enhances the surface temperature anomaly caused by thermal wake.Under the no heat discharge condition,the temperature stratification of the water area is greatly disturbed by a diving maneuvering underwater vehicle,and a cold wake appears.In contrast,due to the influence of heat emission,the thermal wake floats upward as a kidney vortex,the vortex structure scale increases with the sailing distance,and the core temperature decreases with increasing sailing distance.Stratified seawater with a positive temperature gradient enhances the abnormal sea surface temperature characteristics caused by cooling water;the larger the temperature gradient,the more continuous the hot spots.The hot spot has a maximum core temperature of 292.24 K and differs in temperature from the surrounding seawater by 0.12 K.