THERMAL MODELING AND INSIGHTS Workshop at PSL, May 6th-2005 RAGHUNATH GANUGAPATI(NEWT)

DRILL MODEL Energy During drill Heat Pumped to keep the borehole from closing Adaptive 2D mesh setup with 100*10000 steps (Space*Time)(FD used) Movement of boundary(ice-water interface at each depth tracked by the Differential Equation (Stefan Problem)) Energy During drill Instantaneous melting (depends on nozzle design) Slow melting (conduction through the walls of bore hole) Energy by Hose heating (Continuous dependent on hose material) Energy during ream

HOLE-21 DRILLING

The Actual Data From Hole21 VS Prediction

TEMPERATURE PROFILES

OPTIMAL DRILLING The optimal solution should produce a drill speed that leads to a targeted uniform diameter for a target deployment time for a fixed power and other system constraints. In this case, no extra heat would be applied nor any time wasted by drilling too large a hole at any depth, which should be the goal speed (m/hr) Total Energy=538GJ

PROFILE OF OPTIMUM BOREHOLE Target Diameter=45cm

PERTURBATION STUDIES

SMART DRILL Often when narrower or wider regions are seen in the hole.The driller will decide to reduce the speed by certain amount ,this cannot be smooth and precisely timed and we could have OM failure because of uneven holes In order to have a computer make decisions that drill operator would.To learn from its decisions and optimize the strategy and a fully automated system

References Check www.amanda.wisc.edu/newt/monster.doc