Janus spheres are heterogeneous amphiphilic particles having partially slippery and partially sticky surface. As a result, hydrodynamic forces such as drag and lift on a Janus sphere are different from those on a homogeneous sphere. Several applications of Janus particles require high particle concentration in a continuous fluid medium making the interactions between them inevitable. Therefore, in this study three-dimensional flow around two Janus spheres held fixed relative to each other with the line connecting their centres normal to a uniform fluid stream, is investigated computationally at Reynolds numbers ranging from 0.1 to 50. The dependence of lift and drag coefficients on the separation distance between the two Janus spheres is studied. Two cases, (A) sticky hemispheres facing each other and (B) slippery hemispheres facing each other are considered. While for Case A, the spheres repel each other for all the separation distances studied, a cross-over from repulsion to attraction regime with the increase in Reynolds number is observed for Case B. Correlations are proposed for drag at various separation distances for both the orientations.

Janus球是具有部分光滑和部分粘性表面的异质两亲颗粒。结果，Janus球上的水动力（例如阻力和升力）与均质球上的水动力不同。Janus颗粒的几种应用要求在连续的流体介质中具有较高的颗粒浓度，这使得它们之间的相互作用不可避免。因此，在这项研究中，围绕两个Janus球的三维流动相对于彼此保持固定，并且将它们的中心法线连接到均匀的流体流，并在雷诺数为0.1到50的范围内进行了计算研究。升力和阻力的依赖性研究了两个Janus球之间的分离距离的系数。有两种情况 （A）彼此面对的粘性半球和（B）彼此面对的光滑的半球。对于案例A，在研究的所有分离距离下，球体相互排斥，但对于案例B，观察到了随着雷诺数的增加，从排斥力向吸引态的过渡。对于两个不同距离的阻力，都提出了相关性。方向。