The flow stability induced by the impingement of gas jets exiting from the intake manifold affects the in-cylinder flow characteristics of internal combustion engine. Using high-speed planar particle image velocimetry (PIV) with proper orthogonal decomposition (POD) analysis, an investigation was conducted to reveal the spatio-temporal characteristics of annular gas jets impinging in a region between the exits of two intake valves. Unique flow behaviors are identified where strong initial interaction of impinging jets appears near the valve exit as a result of fierce flow vorticity competition in both clockwise and counter-clockwise directions. This mixing zone exhibits strong fluctuations in the angle of the merged gas jet. Flow vorticity and merged jet angle are highly correlated with each other, and the quasi-periodical behavior of the jet impingement is linked to the kinetic energy dissipation. In addition, using POD, the underlying flow structures show large-scale rotating structures with translation which are responsible for the quasi-periodical behavior. In summary, three types of flow stability can be identified resulting from different levels of induced impingement: one-way interaction of single jet flow case, two-way interaction of dual impinging jets with equal flow magnitude, and transitional one-way interaction of dual impinging jets with unequal flow magnitude.

由从进气歧管流出的喷气的冲击引起的流动稳定性影响内燃机的缸内流动特性。使用带有适当正交分解（POD）分析的高速平面粒子图像测速（PIV），进行了一项研究，以揭示撞击在两个进气门出口之间的区域中的环形气体射流的时空特性。在顺时针和逆时针方向上激烈的流涡竞争的结果是，在阀出口附近出现冲击射流的强烈初始相互作用的地方，可以识别出独特的流动行为。该混合区在合并的气体射流的角度上表现出强烈的波动。流动涡度和合并的射流角彼此高度相关，射流冲击的准周期行为与动能耗散有关。此外，使用POD，下面的流动结构显示出具有平移的大规模旋转结构，这是准周期性行为的原因。总而言之，可以从不同程度的感应撞击中识别出三种类型的流动稳定性：单喷流情况下的单向相互作用，等流量的双撞击喷头的双向相互作用以及双喷头的过渡单向相互作用不等流量的撞击射流。