ambient medium meaning in English

环境介质
周围介质

When the hydrodynamic front reaches the ambient medium it acts like a fast-moving piston .
当流体力学波阵面抵达周围介质时，它像一个运动迅速的活塞。
In the light of the interaction of oil ， pipeline and ambient media and their unstable heat transmission ， considering temperature dependent on physical properties and phase change of oil ， a mathematical model for thermal calculation is presented
针对加热原油管道停输后油品、管道及周围介质的相互关系和它们的不稳定传热，提出了热力计算的数学模型。