Impinging liquid jets are widely used to clean unwanted soil layers from the walls of structures and vessels. When the soil is a thin layer of an immiscible viscoplastic material, removal involves the growth of a cleared area (which is circular for a jet impinging normally) bounded by a berm of displaced material. Glover et al. [1] presented a semi-empirical model relating the rate of removal to the momentum flow rate in the liquid film. We present a first-order model for cleaning thin layers of these materials based on the rate of viscous dissipation in a shallow wedge of material at the cleaning front. This yields a result of the form of the model in [1], with expressions linking the kinetic parameters to measurable quantities including the rheology of the soil. The fully coupled problem is not solved: the wedge angle and residual layer thickness need to be specified and were obtained here by fitting to the data. The model is compared with experimental results obtained for three soft solids – two petroleum jellies and a soft paraffin – which exhibited Bingham plastic behaviour and creep, for jet Reynolds numbers between 10,000-37,000, and $0.1<\overline{h}/{\delta }_{\mathrm{o}}<1.5,$ where $\overline{h}$ is the average film depth and δ_o the layer thickness. The data show reasonable agreement with the model.

撞击式液体喷射器广泛用于从结构和容器壁上清除多余的土壤层。当土壤是不混溶的粘塑性材料的薄层时，清除工作涉及到由被置换的材料的护壁所包围的清理区域（对于正常撞击的射流来说是圆形的）的生长。Glover等。[1]提出了一个半经验模型，将去除速率与液膜中的动量流速相关联。我们基于清洁前沿材料的浅楔形中的粘性耗散率，提出了用于清洁这些材料薄层的一阶模型。这产生了[1]中模型形式的结果，其表达式将动力学参数与包括土壤流变学在内的可测量量联系起来。完全耦合的问题无法解决：需要指定楔角和残余层厚度，并在此处通过拟合数据获得。该模型与三种软固体（两种石油胶和一种软石蜡）的实验结果进行了比较，三种软固体表现出宾汉的塑性和蠕变，雷诺数为10,000-37,000，并且$0.1<\overline{H}/{\delta }_{\mathrm{Ø}}<1.5，$ 哪里 $\overline{H}$是平均膜深度和δ _ö层厚度。数据表明与模型合理吻合。