Browsing by Author "Singh, K."

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Experimental and numerical investigation of pool boiling heat transfer from finned surfaces
(Elsevier Ltd, 2023) Jaswal, R.; Sathyabhama, A.; Singh, K.; Yandapalli, A.V.V.R.P.
An experimental study of the pool boiling process on three test surfaces, namely, Plain surface, Rectangular finned surface, and Trapezoidal finned surface, was carried out using distilled water as the working fluid at atmospheric pressure. A parametric study of finned surfaces was performed to understand the effect of fin spacing and fin height on the pool boiling performance. A high-speed camera was employed to capture the pool boiling process. A numerical investigation was also performed using the Eulerian multiphase model associated with the RPI wall boiling model. A 2-D rectangular boiling chamber filled with distilled water was considered for the numerical study. The numerical results with default models were validated with the experimental results. A correction was proposed for the Bubble Waiting Time coefficient (Cw) of the quenching heat flux to improve the numerical results. Experimental results showed that using rectangular and trapezoidal finned surfaces improved the heat flux values by 52.3% and 101.5%, respectively, compared to the plain surface. The heat transfer coefficient (HTC) depends upon the area availability and type of boiling surface used. Increasing the height of the fins was beneficial, whereas increasing the fin spacing adversely affected the fin performance. © 2023 Elsevier Ltd
Influence of temperature on MWCNT bundle, SWCNT bundle and copper interconnects for nanoscaled technology nodes
(2015) Singh, K.; Raj, B.
This paper presents the comparative analysis of temperature dependent performance of Multi-walled carbon nanotubes (MWCNT), Single-walled carbon nanotube (SWCNT) and copper interconnects for nanoscaled technology nodes. The temperature dependent impedance circuit model is proposed for MWCNT bundle interconnects. The proposed model for MWCNT bundle shows the various electron phonon scattering mechanisms dependency as a function of temperature. The performance in terms of propagation delay, power dissipation and power delay product for MWCNT bundle interconnects is simulated on the basis of temperature dependent electrical parameters for global interconnects at three different technology nodes viz. 32, 22 and 16 nm for temperature range 200 to 450 K. A similar analysis is performed for SWCNT bundle and copper interconnects and results are compared with the MWCNT bundle interconnects. The comparative results revealed that the performance of MWCNT bundle interconnects is better than the performance of SWCNT bundle and copper interconnects at different temperature ranging from 200 to 450 K for 32, 22 and 16 nm technology nodes at global interconnects. 2015, Springer Science+Business Media New York.
Modelling of Subcooled Boiling in Corrugated Pipes
(Springer Science and Business Media Deutschland GmbH, 2023) Madan, K.; Singh, K.; Sathyabhama, A.
This paper presents a numerical investigation of subcooled flow boiling heat transfer in sinusoidal-corrugated vertical pipes using RPI wall boiling with Eulerianâ€“Eulerian two-phase flow model. Numerical studies are performed for different values of corrugation length and wall heat flux at a constant mass flux, operating pressure and temperature which are representative of steam generation in nuclear reactors. The numerical results are also compared with the smooth/flat pipe in terms of wall temperature, heat transfer, pressure drop and volume fraction (vf) of vapour. The results showed that onset of nucleate boiling is delayed in the case of corrugated pipes as compared to the flat pipe. It is also observed that the vf of vapour at the outlet of flat pipe is higher as compared to corrugated pipes. Overall heat transfer is increased in corrugated pipes due to enhanced mixing which eventually improved convective heat transfer. However, improvement in the heat transfer is at the cost of pressure drop. Â© 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Numerical simulation of progressive fracture propagation in petroleum reservoir rock strata using finite element modeling
(2014) Goyal, R.; Singh, K.; Reddyy, D.V.
Reservoir perforation allows for interfacing of the pay-zone and the production casing in the petroleum wellbore. Perforations are key interface for fluid movement in completion and they are extremely important for effective design and itis to beensured that well has appropriate number and size of perforation. For directing formation petroleu mfluid from subsurface zone, cased well must be perforated. Perforationis created by implementing controlled detonation of steel casing, cement casing and surrounding rock using specially design edand manufactured shaped charges. Perforating shockwaves and high impact pressureshattertherockto breakdown and propagate crack through it. Numerical model of acuboidal rock sample is createdto decide the preferred fracture plane. Under balance forces have also been taken in account to calculate Von-misesstress. Simulations are performed in order tostudy the behavior of compound stress during chargede to nation of rock and casing fracture. Crack propagation in different directions and principal planes has been found out. Usingthese results, location ofchargesoncasingcanbe defined to propagate fracture indesired locations. This report presents numerical analysis of fracture propagation during charged detonation using finite element methods (FEM).. 2014 CAFET-INNOVA TECHNICAL SOCIETY.
Numerical simulation of progressive fracture propagation in petroleum reservoir rock strata using finite element modeling
(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2014) Goyal, R.; Singh, K.; Reddyy, D.V.
Reservoir perforation allows for interfacing of the pay-zone and the production casing in the petroleum wellbore. Perforations are key interface for fluid movement in completion and they are extremely important for effective design and itis to beensured that well has appropriate number and size of perforation. For directing formation petroleu mfluid from subsurface zone, cased well must be perforated. Perforationis created by implementing controlled detonation of steel casing, cement casing and surrounding rock using specially design edand manufactured shaped charges. Perforating shockwaves and high impact pressureshattertherockto breakdown and propagate crack through it. Numerical model of acuboidal rock sample is createdto decide the preferred fracture plane. Under balance forces have also been taken in account to calculate Von-misesstress. Simulations are performed in order tostudy the behavior of compound stress during chargede to nation of rock and casing fracture. Crack propagation in different directions and principal planes has been found out. Usingthese results, location ofchargesoncasingcanbe defined to propagate fracture indesired locations. This report presents numerical analysis of fracture propagation during charged detonation using finite element methods (FEM).. © 2014 CAFET-INNOVA TECHNICAL SOCIETY.
Performance and analysis of temperature dependent multi-walled carbon nanotubes as global interconnects at different technology nodes
(2015) Singh, K.; Raj, B.
A temperature dependent performance in terms of power delay product (PDP) of multi-walled carbon nanotube (MWCNT) bundle interconnect has been analyzed for temperature range from 200 to 450 K at three different technology nodes viz. 32, 22 and 16nm. A similar analysis is performed for copper interconnect and results are compared with MWCNT bundle interconnect. Comparative results revealed that delay and PDP is increased with rise in temperature ranging from 200 to 450 K. It has also been observed that the temperature dependent MWCNT bundle interconnect gives better performance in terms of delay, power and PDP as compared to copper interconnect for three technology nodes at global interconnect length. 2015, Springer Science+Business Media New York.
Quarter circular breakwater: Prediction of transmission using multiple regression and artificial neural network
(2014) Goyal, R.; Singh, K.; Hegde, A.V.
The physical model study of coastal structures is a nonlinear process influenced by innumerable parameters. As a result of a lack of definite systems, intricacies, and high costs involved in the physical models, we need a simple mathematical tool to predict wave transmission through quarter circular breakwater (QBW). QBW is a state-of-theart breakwater essentially based on the exploitation of the concepts of semicircular breakwater. This paper discusses the use of soft computing tools such as MATLAB based multiple regression (MR) and artificial neural network (ANN) to predict the wave transmission coefficient of QBW. To assess the accuracy of the proposed model and its ability to forecast, correlation coefficient and mean squared error are availed. On comparing the results obtained from MR and ANN, it is concluded that ANN gives more accurate results and can be used as a powerful tool for the modeling of hydrodynamic breakwater transmission through QBW. It serves as a viable alternative to the conventional physical model to simulate the hydrodynamic transmission performance of QBW.
Quarter circular breakwater: Prediction of transmission using multiple regression and artificial neural network
(Marine Technology Society Inc. mtsdir@erols.com, 2014) Goyal, R.; Singh, K.; Hegde, A.V.
The physical model study of coastal structures is a nonlinear process influenced by innumerable parameters. As a result of a lack of definite systems, intricacies, and high costs involved in the physical models, we need a simple mathematical tool to predict wave transmission through quarter circular breakwater (QBW). QBW is a state-of-theart breakwater essentially based on the exploitation of the concepts of semicircular breakwater. This paper discusses the use of soft computing tools such as MATLAB based multiple regression (MR) and artificial neural network (ANN) to predict the wave transmission coefficient of QBW. To assess the accuracy of the proposed model and its ability to forecast, correlation coefficient and mean squared error are availed. On comparing the results obtained from MR and ANN, it is concluded that ANN gives more accurate results and can be used as a powerful tool for the modeling of hydrodynamic breakwater transmission through QBW. It serves as a viable alternative to the conventional physical model to simulate the hydrodynamic transmission performance of QBW.