@the university of tokyo, japan
Project Researcher, Nuclear Professional Group, The Univeristy of Tokyo, Japan
Project Researcher
Experienced Project Researcher specializing in the fields of thermal management and fluid mechanics. Expertise spans both practical experimentation and advanced computational analysis, focusing on effective problem solving. Highly adaptable, thrive in diverse work environments, excelling both as independent contributor and collaborative team member. Career highlights include over 40 international publications, showcasing a strong track record of punctuality and reputation for offering technical guidance and making informed decisions.
• Ph.D. in Mechanical Engineering (Thermal & fluid flow) from Indian Institute of Technology Indore, INDIA, GPA 8.63 (Jan 2020).
• Master of Technology (MTech) in Energy from Indian Institute of Technology Jodhpur, INDIA, GPA 7.83 (Sep 2014).
• Bachelor of Technology (BTech) in Mechanical Engineering from Government Engineering College Bikaner, INDIA, 65.87% (Aug 2012).
Mechanical Engineering, Safety, Risk, Reliability and Quality, Fluid Flow and Transfer Processes, Colloid and Surface Chemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Zhenhan Hong, Zeeshan Ahmed, Marco Pellegrini, Hidemasa Yamano, Nejdet Erkan, Avadhesh Kumar Sharma, and Koji Okamoto
Elsevier BV
Zeeshan Ahmed, Avadhesh Kumar Sharma, Marco Pellegrini, Hidemasa Yamano, Sho Kano, and Koji Okamoto
Elsevier BV
Rui-Cong Xu, Avadhesh Kumar Sharma, Erdal Ozdemir, Shuichiro Miwa, and Shunichi Suzuki
Springer Science and Business Media LLC
AbstractDuring the decommissioning of the Fukushima Daiichi nuclear power plant, it is important to consider the retrieval of resolidified debris both in air and underwater configurations. For the subsequent retrieval of debris from the reactor building, the resolidified debris must be cut into smaller pieces using various cutting methods. During the cutting process, aerosol particles are expected to be generated at the submicron scale. It has been noted that such aerosols sizing within the Greenfield gap (0.1–1 μm) are difficult to remove effectively using traditional spraying methods. Therefore, to improve the aerosol removal efficiency of the spray system, a new aerosol agglomeration method was recently proposed, which involves injecting water mist to enlarge the sizes of the aerosol particles before removing them using water sprays. In this study, a series of experiments were performed to clarify the proper spray configurations for effective aerosol scavenging and to improve the performance of the water mist. The experimental results showed that the spray flow rate and droplet characteristics are important factors for the aerosol-scavenging efficiency and performance of the water mist. The results obtained from this study will be helpful for the optimization of the spray system design for effective aerosol scavenging during the decommissioning of the Fukushima Daiichi plant.
Yosuke Nishimura, Anna Gubarevich, Katsumi Yoshida, Avadhesh Kumar Sharma, and Koji Okamoto
Elsevier BV
Avadhesh Kumar Sharma, Wataru Sagawa, Zeeshan Ahmed, Yosuke Nishimura, and Koji Okamoto
Elsevier BV
Avadhesh Kumar Sharma, Ruicong Xu, Zeeshan Ahmed, Shuichiro Miwa, Benjamin Blaisot, Shunichi Suzuki, Hui Liang, and Nejdet Erkan
Elsevier BV
Hui Liang, Nejdet Erkan, Kai Wang, Avadhesh Kumar Sharma, and Shunichi Suzuki
Elsevier BV
Yosuke Nishimura, Anna Gubarevich, Katsumi Yoshida, Avadhesh Kumar Sharma, and Koji Okamoto
Informa UK Limited
Avadhesh Kumar Sharma, Hui Liang, Ruicong Xu, Erdal Ozdemir, Shuichiro Miwa, Ryohei Terabayashi, Shunichi Suzuki, Marco Pellegrini, Shuichi Hasegawa, and Nejdet Erkan
Informa UK Limited
Abstract The recent Nuclear Regulation Authority evaluation report suggests that at the Fukushima Daiichi Nuclear Power Station, the concrete shield plugs above the primary containment vessel (PCV) have exceptionally high radiation levels in Units 2 and 3, which may increase the risk of radiation exposure during decommissioning operations. During the cleaning and disassembly of such radiation hot spots, it is expected that a large amount of submicron-sized radioactive aerosol particles will be generated, which may influence the decommissioning operation. In the present study, laser cleaning experiments were conducted at the University of Tokyo Aerosol Removal Test Facility to simulate aerosol scavenging during the laser cleaning process. The facility can reproduce multiple phenomena expected in actual plant decommissioning, such as laser decontamination and simultaneous mist and spraying operations. Through the work, we have developed effective aerosol dispersion control methods and strategies based on the joint use of water mist and water spray to reduce radiation risk in either laser cutting or other means of decontamination methods. Preliminary laser cleaning experiments on various coated samples were conducted to assess the aerosol removal efficiency using water droplets and mist. It was verified that the proposed method effectively cleans the radiation hot spots during the decommissioning process.
Avadhesh Kumar Sharma, Marco Pellegrini, Koji Okamoto, Masahiro Furuya, and Shinya Mizokami
Elsevier BV
Hui Liang, Erkan Nejdet, Kai Wang, Avadhesh Kumar Sharma, and Shunichi Suzuki
American Society of Mechanical Engineers
Abstract In the future decommissioning plan of the damaged Fukushima Daiichi nuclear reactors, the melted and re-solidified fuel debris at the bottom of the reactor pressure vessel and primary containment vessel will be cut into small pieces before retrieving them from reactor buildings. Submicron aerosol particles that generated during cutting operations must be removed inside the containment vessel before they escape to the environment. The existed spray system inside the containment vessel can be used to remove these aerosol particles under different collection mechanisms. In this study, a new numerical model is developed to simulate both the aerosol generation by cutting fuel debris and aerosol removal by spray injection in the open-source CFD code OpenFOAM using the geometry of our model facility (UTARTS facility). Simulation results provide detailed information about the time evolution of aerosol distribution, and also show that aerosol generation rate has no influence on aerosol removal efficiency, and larger particles can be removed faster because of stronger inertial impaction. The newly developed numerical model with considering both aerosol generation due to cut fuel debris and aerosol scavenging by spray droplets can be used in the real-size containment vessel of Fukushima Daiichi nuclear reactors to optimize the design of future spray systems.
Maheandera Prabu Paulraj, Santosh Kumar Sahu, Avadhesh Kumar Sharma, Anuj Kumar, Karthikeyan Sengadurai, and I. A. Palani
Springer Singapore
Avadhesh Kumar Sharma, Mayank Modak, Santosh Kumar Sahu, and Manish Kumar Agrawal
Springer Singapore
Avadhesh Kumar Sharma, Umesh Kumar Lodhi, Gautam Kumar, and Santosh Kumar Sahu
Wiley
The thermal and rewetting behavior of downward‐facing hot surfaces with single upward oblique liquid jet impingement is studied through experimental investigation. The Reynolds number varies in the range of 2500–10 000 and the jet inclination angle varies from 90° to 15°, measured from the horizontal. The current study uses a stainless‐steel foil (SS‐304) with 0.15 mm thickness as the test specimen, and a thermal imaging technique is used to measure temperature data during jet impingement cooling. The initial surface temperature of the test foil is maintained at 500 ± 10 °C and the standoff distance is kept at 6 mm. The Nusselt number is found to increase in the downhill direction and decrease sharply in the uphill direction with the decrease in the inclination angle. The wet‐front velocity is found to increase in the downhill direction with the decrease in the inclination angle. Correlations are proposed for Nusselt number and rewetting temperature as a function of Reynolds number, jet inclination angle, and axial distance.
Avadhesh Kumar Sharma and Santosh Kumar Sahu
Elsevier BV
Avadhesh Kumar Sharma and Santosh Kumar Sahu
Elsevier BV
Mayank Modak, Avadhesh Kumar Sharma, and Santosh K. Sahu
Informa UK Limited
ABSTRACT The present article reports the heat transfer characteristics of a vertical stainless steel foil of 0.15 mm thickness (SS304) by circular impinging jets of various fluids such as pure water, nano-fluids (Al2O3-water, ф = 0.15%, 0.6%), and aqueous high-alcohol surfactant (HAS, i.e., 2-ethyl-hexanol, 100–400 ppm) studied using an infrared thermal imaging camera (A655sc, FLIR System). The enhancement in the heat transfer rates for Al2O3-water nano-fluids with ф = 0.15%, ф = 0.60%, and aqueous surfactant solution (150ppm) is found to be 140%, 207%, and 117% higher compared to pure water results, respectively. The surface characteristics of the foil after jet impingement by various fluids are also studied using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and surface wettability.
Avadhesh Kumar Sharma, Mayank Modak, and Santosh Kumar Sahu
Elsevier BV
Avadhesh Kumar Sharma, Monika Meena, Anirudh Soni, and Santosh K. Sahu
American Society of Mechanical Engineers
The jet impingement cooling is always preferred over the other cooling methods due to its high heat removal capability. However, rapid quenching may lead to the formation of cracks and poor ductility to the quenched surface. Mist jet impingement cooling offers an alternative method to uncontrolled rapid cooling, particularly in steel and electronic industries. In mist cooling, the droplets are atomized by compressed air. Experiments are performed under transient conditions using two full-cone spray nozzles (Lechler Pneumatic atomizing nozzle 136.115.xx.A2 and 136.134.xx.A2) to study the effect of subcooling and nozzle diameter on surface heat flux. The hot surface used for the experiment is a stainless steel foil (AISI-304) of thickness 0.15mm. The initial surface temperature of the plate is maintained at 500±10°C with the help of an AC transformer. Infrared thermal image camera (A655sc, FLIR System) is used for data estimation. The IR camera and the nozzle are positioned on either side of the plate. The variation in surface temperature has been acquired at 8 different spatial points. It has been observed that that as we move away from the stagnation point then irrespective of air and water flow rates surface heat flux decreases. The maximum surface heat flux obtained at the stagnation point. With the increase in diameter surface heat flux increases irrespective of pressure values. The correlation between qm/qstag experimental and predicted values has been shown.
Avadhesh Kumar Sharma, Mayank Modak, and Santosh K. Sahu
American Society of Mechanical Engineers
Impinging jets are commonly utilized in the run-out table (ROT) cooling in the hot rolling process in steel manufacturing industries. The phenomenon of rapid cooling of a sufficiently hot surface is termed as the quenching. The present paper reports the rewetting behavior of 0.15 mm thick hot moving stainless steel foil (SS-304) by circular impinging jet from bottom side through experimental investigation. The transient temperature of the hot foil is recorded by using thermal imaging camera (A655sc, FLIR system). Tests are performed for a varied range of Reynolds number (Re = 2500–10000), nozzle to plate distance (z/d = 6), moving plate velocity (0–40 mm/s) and initial surface temperature 500±10 °C. Transient temperature obtained from thermal imaging camera is used to evaluate rewetting time and rewetting velocity. Based on the experimental investigation correlation has been proposed to predict non-dimensional rewetting velocity as a function of various parameters, namely, Reynolds number, non-dimensional axial distance and moving plate velocity.
Vishal V. Nirgude, Mayank Modak, Avadhesh K. Sharma, and Santosh K. Sahu
American Society of Mechanical Engineers
In the present experimental study an attempt has been made to study the boiling heat transfer characteristics of variety of enhanced surfaces. Three different copper test surfaces: polished copper and two structured surfaces were used in the present investigation. The heat transfer performance of each surface is studied under saturated pool boiling conditions at atmospheric pressure by using water and isopropyl as pool liquid. The effect of intersecting tunnel geometry with 0.5 mm and 1 mm depth on heat transfer performance has been studied. The comparison of heat transfer coefficient indicates that the intersecting tunnel structure enhanced the boiling heat transfer performance and reduced the wall superheat at given heat flux inputs.
Ashutosh Kumar Yadav, Parantak Sharma, Avadhesh Kumar Sharma, Mayank Modak, Vishal Nirgude, and Santosh K. Sahu
American Society of Mechanical Engineers
Impinging jet cooling technique has been widely used extensively in various industrial processes, namely, cooling and drying of films and papers, processing of metals and glasses, cooling of gas turbine blades and most recently cooling of various components of electronic devices. Due to high heat removal rate the jet impingement cooling of the hot surfaces is being used in nuclear industries. During the loss of coolant accidents (LOCA) in nuclear power plant, an emergency core cooling system (ECCS) cool the cluster of clad tubes using consisting of fuel rods. Controlled cooling, as an important procedure of thermal-mechanical control processing technology, is helpful to improve the microstructure and mechanical properties of steel. In industries for heat transfer efficiency and homogeneous cooling performance which usually requires a jet impingement with improved heat transfer capacity and controllability. It provides better cooling in comparison to air. Rapid quenching by water jet, sometimes, may lead to formation of cracks and poor ductility to the quenched surface. Spray and mist jet impingement offers an alternative method to uncontrolled rapid cooling, particularly in steel and electronics industries. Mist jet impingement cooling of downward facing hot surface has not been extensively studied in the literature. The present experimental study analyzes the heat transfer characteristics a 0.15mm thick hot horizontal stainless steel (SS-304) foil using Internal mixing full cone (spray angle 20 deg) mist nozzle from the bottom side. Experiments have been performed for the varied range of water pressure (0.7–4.0 bar) and air pressure (0.4–5.8 bar). The effect of water and air inlet pressures, on the surface heat flux has been examined in this study. The maximum surface heat flux is achieved at stagnation point and is not affected by the change in nozzle to plate distance, Air and Water flow rates.