Sateesh Gedupudi

Bio: Sateesh Gedupudi is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Heat transfer coefficient & Heat transfer. The author has an hindex of 10, co-authored 50 publications receiving 412 citations. Previous affiliations of Sateesh Gedupudi include Brunel University London.

Development of Compact Multivariable Probe for Two-Phase Detection in PbLi-Argon Columns

Abstract: Liquid gas two phase flow is a common occurrence in various industrial applications. For nuclear fusion applications with a Li based breeder, existence of two phase flow may lead to critical issues including decreased tritium breeding ratio, generation of hot spots and improper nuclear shielding. Additionally, a very large density ratio of liquid metal to gas mandates relevant experiments towards development and validation of software tools. PbLi has gained immense focus for its various advantages and is utilized in several breeding blanket concepts. In view of above mentioned requirements, a two phase detection tool is imperative for liquid PbLi environment. For liquid metal applications, electrical conductivity based probes are most suitable in terms of ruggedness, fabrication ease and operational simplicity. However, corrosive nature and high operational temperature for PbLi put severe demands on electrical insulation, a foremost requirement for electrical conductivity based schemes. In this study, a multivariable probe based on electrical conductivity and temperature measurement schemes is developed using Al2O3 coating as electrical insulation. Developed probe is validated in PbLi/Ar vertical column with bulk PbLi temperature upto 400 degC and time averaged void fraction upto 0.95 covering flow regimes from dispersed bubbly flow upto in box loss of coolant accident. Developed probe provides high reliability and excellent temporal resolution towards individual bubble detection through electrical conductivity based principle alongwith simultaneous two phase temperature trends. Present paper provides details about sensor probe fabrication, calibration, two phase test facility, void fraction estimations, bubble frequency and bubble residence time estimations alongwith critical observations from preliminary experimental investigations.

Fabrication Aspects and Performance Characterization of α-Al2O3/ALPO4 Based Sandwich Configuration Flow Channel Inserts and Coatings for High Temperature Liquid Metal Applications

Abstract: Liquid metals (LMs) exhibit several key characteristics justifying their utilization as coolants/breeders for nuclear fusion reactors and advanced fission reactors. In a fusion reactor, LMs confront a large flow retarding MHD force, imposing significant demands on pumping power and designs of ancillary systems. Corrosion of structural materials and coolant chemistry control are vital issues common to both fusion and fission reactors employing liquid lead (Pb) and its alloys. To address these concerns, technological solutions such as Flow Channel Inserts and corrosion resistant coatings are being investigated to provide a chemical/electrical isolation between LM and structural material. In this study, three prototype geometries (circular, square and 90 bend) of steel-insulator-steel FCIs are fabricated and an electrical insulation characterization is performed over a temperature range of 100C - 600C. Welding trials and pressure tests are performed to validate the electrical and mechanical integrity over typical fusion reactor operational regime. This paper presents detailed fabrication aspects along with quantitative estimations of insulation filling density, electrical insulation performance and, for the first time, a systematic study of insulation degradation owing to combined effects of TIG welding, pressure and machining operations. Critical details derived from metallurgical examinations and destructive tests are also presented. From implementation perspective towards LFRs, a feasibility assessment of a-Al2O3/AlPO4 thin film coating deposition on planar and non-planar substrates is performed followed by its mechanical characterizations. Detailed metallurgical analyses are presented to assess Pb ingress after 700 hour exposure to molten Pb alloy.