Publication Date:
2014-05-09
Description:
Supercritical water jets are of interest for the hydrothermal spallation drilling technology to thermally fragment rock. The important thermal field of such jets was investigated via axial temperature measurements inside a high-pressure vessel simulating the harsh pressure and temperature conditions found downhole. Deionized water was electrically preheated to supercritical temperatures and afterwards discharged into a slowly co-flowing cooling water ring. Furthermore, a numerical model was developed and applied. Difficulties in simulating the thermal field due to the strongly varying fluid properties around the pseudo-critical point of water were highlighted and critically discussed. An approach of a locally varying turbulent Prandtl number is introduced to improve the predictions compared to the experiment. Finally, all numerical results were validated with experimental data. Due to the strongly varying fluid properties of water around the pseudo-critical point, difficulties in simulating the thermal field of submerged supercritical water jets were detected. A locally varying turbulent Prandtl number was implemented to significantly improve numerical predictions with respect to axial temperature measurements
Print ISSN:
0930-7516
Electronic ISSN:
1521-4125
Topics:
Chemistry and Pharmacology
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Process Engineering, Biotechnology, Nutrition Technology
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