活性剂对水下航行体减阻特性的影响

为减小水下航行体的阻力,研究通活性剂溶液的水下航行体湍流减阻的流动特性.通过从航行体头部向航行体边界通活性剂溶液的方法,分别对不同质量浓度和不同速度情况进行减阻实验研究,并分析了不同攻角下活性剂溶液对阻力和升力的影响.实验中活性剂溶液质量浓度分别为200、400、600、800和1 000 mg/L,流速为4~10 m/s,对比分析了阻力系数.实验结果表明:在活性剂溶液质量浓度为200 mg/L时航行体减阻效果较弱,当活性剂溶液质量浓度增加到1 000 mg/L时,减阻百分比高达40.8%;在活性剂质量浓度为1 000 mg/L时,当水流速度从4 m/s逐渐增大到10 m/s,减阻百分比在12.5%和40.8%之间变化;活性剂对有攻角的航行体仍然有减阻效果并且对升力产生较小影响.

Influence of surfactant on drag reduction characteristic of an underwater vehicle

To reduce the drag of underwater vehicle, experiment is carried out to study the turbulent drag-reducing of underwater vehicle injected with surfactant in a water tunnel. For the experimental work presented here, surfactant is injected from the head of the vehicle. The drag reduction (DR) of surfactant as a function of fluid velocity and surfactant concentration are investigated. The influences of the surfactant on the lift-force and drag-force with different attack angle are analyzed. Surfactant solutions at different concentrations, namely 0,0, 0,0 and 1000 mg/L, are used to examine the influence of surfactant on drag coefficient. The flow velocities are set between 4 and 10 m/s. The present results show the DR effect is weak when the surfactant concentration is 200 mg/L. With the increase of the surfactant concentration to 1 000 mg/L, the drag coefficient is reduced by about 40.8%. The DR ratio ranges between 12.5% and 40.8% at all flow velocities up to 10 m/s from 4 m/s when the surfactant concentration is 1 000 mg/L. With the increase of surfactant concentration, the drag coefficient of the vehicle with angle of attack is also reduced and there is slight effect on the lift-force coefficient.