Experimental and Numerical Study on Air Flow Behavior for a Novel Retractable Reverse Circulation Drill Bit of Casing-while-Drilling (CwD)

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static-preview.hindawi.com/articles/geofluids/volume-2021/3586572/figures/3586572.fig.004a.svgz" name="3586572.fig.004a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>Geometric models</td></tr><tr class="fig-image" id="b"><td><object data="https://static-preview.hindawi.com/articles/geofluids/volume-2021/3586572/figures/3586572.fig.004b.svgz" name="3586572.fig.004b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b>Computation grids</td></tr><tr class="fig-image" id="c"><td><object data="https://static-preview.hindawi.com/articles/geofluids/volume-2021/3586572/figures/3586572.fig.004c.svgz" name="3586572.fig.004c" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(c) </b>Partial enlarged grid diagram</td></tr></table>

<div>Geometric models and computation grids for the retractable drill bit with reverse circulation.</div>

Geofluids

fig4

Figure 4

Figure 4: Experimental and Numerical Study on Air Flow Behavior for a Novel Retractable Reverse Circulation Drill Bit of Casing-while-Drilling (CwD) 