ravi babu sajja

@gmrit.org/profiles

Associate Professor, Mechanical Engineering
GMR Institute of Technology



              

https://researchid.co/ravibabu.s

Babu is having more than 20 years of total experience.

EDUCATION

M.Tech, Ph.D

RESEARCH INTERESTS

Heat tansfer augmentation, nanofluids, convection heat transfer

18

Scopus Publications

116

Scholar Citations

6

Scholar h-index

4

Scholar i10-index

Scopus Publications


  • Effect of Inclination and Thermoelectric Material on the Performance of Solar PV-Thermo Electric Cooling System
    Sajja Ravi Babu, Shaik Ahammad Basha, Gnanasekaran Sasikumar, and Prathipati Pradeep Kumar
    Wydawnictwo Naukowe Gabriel Borowski (WNGB)
    Solar photovoltaic (PV) systems, coupled with thermo-electric cooling, have gained significant attention as an eco-friendly solution. To enhance energy efficiency and reduce the overall environmental impact of energy generation and consumption, it is a viable option. This study investigates the impact of critical parameters, namely inclination angle of solar panels, the type of material used in thermo-electric cooling modules, on the performance of a solar PV-thermo electric cooling system. In this research, the impact of inclination angles (15°, 20°, 25°) and two materials (Bismuth telluride and Peltium telluride) of thermoelectric were considered for this study. A comprehensive series of experiments were conducted to analyze the impact of varying inclination angles of the solar panels and material of thermoelectric cooler. The average incident irradiation, panel temperature and outpower of solar panel variation with time are presented. The optimum tilt angle of the solar panel is observed as 20° and material for thermoelectric cooler is Bismuth telluride. When using Bismuth telluride as a thermoelectric material with 20° tilt angle, the solar panel’s temperature decreases by 14% and its outpower is augments by a maximum of 14.5%. The results presented here offer practical guidance for system design and operation, ultimately promoting the widespread adoption of this technology in a more environmentally conscious manner.

  • Wastewater Treatment Technologies Selection Using Analytical Hierarchy Process and VIKOR Methods: A Case Study
    Gnanasekaran Sasikumar, A. Sivasangari, and S. Ravibabu
    Technoscience Publications
    Due to the ever-increasing water scarcity problem across the globe, the treatment of wastewater is an important public health and socio-economic issue. Treating wastewater through proper technology is vital to protect the ecosystem from unsafe and contaminated matter available in wastewater. Identification of suitable wastewater treatment technologies is a complex Multi-Criteria Decision Making (MCDM) problem since it includes many conflicting assessment criteria. The objective of the paper is to construct an integrated model using the Analytical Hierarchy Process (AHP) and VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) for evaluating wastewater treatment technologies (WWTTs). AHP is applied to calculate criteria weights, and the VIKOR method is applied to prioritize and select the best WWTTs. The proposed model is applied to selecting the best WWTT among four alternatives and seven criteria. It is found that the proposed model yields better results when compared with other MCDM solutions.

  • Nanofluid selection for an automobile radiator using weighted sum model technique
    S. Ravi Babu, K. P. V. Krishna Varma, and P. Ramesh Babu
    AIP Publishing

  • Wear Analysis of Iron Slag Reinforced Polyester Composites with Taguchi Optimization
    Nimmagadda Vijaya Kumar, Shaik Ahammad Basha, Chitikena Chaitanya Kishore, Potli Aswarthanarayana, Prathipati Pradeep Kumar, Marthati Maruthi Rao, and Sajja Ravi Babu
    Wydawnictwo Naukowe Gabriel Borowski (WNGB)
    In this paper, the dry sliding wear behaviour of the polyester composite reinforced with iron slag as filler was studied experimentally. The Taguchi method-based experiments were carried on pin-on-disk wear test set-up. The control factors considered for studying wear rate were sliding velocity, slag percentage and normal load applied on the member with constant sliding distance. The output performance parameters considered were coefficient of friction and weight loss. From the analysis of variance (ANOVA), it was observed that coefficient of friction is sig - nificantly affected by normal load then followed by slag content and sliding velocity. Sliding velocity plays a vital role on the weight loss, then followed by slag content and normal load. The optimal factor combination obtained was sliding velocity = 50 cm/s, slag percentage = 30 % and normal load = 4 kg. The model was validated using the set of optimal factor combinations to conduct a confirmation experiment.

  • Experimental Investigation on Free Convective Heat Transfer Performance of Oxide Nanofluids Along a Vertical Cylinder
    S. Ravi Babu, P. Pradeep Kumar, S.A. Basha, and M. Maruthi Rao
    Wydawnictwo Naukowe Gabriel Borowski (WNGB)
    The multi criterion decision making (MCDM) method and experimental investigation on free convective heat transfer performance of oxide-based water nanofluids along a vertical cylinder are the two methods used to com - pare the performance in this paper. Al 2 O 3 , CuO, TiO 2 , SiO 2 , Fe 3 O 4 , and ZnO were the metal oxide nanoparticles used in the study to make water-based metal oxide nanofluids with volume fractions ranging from 0% to 1%. Two step method was used to create nanofluids. Thermo-physical properties like density, specific heat, viscosity, and thermal conductivity were measured after the various nanofluids were synthesized. Then, the performance of each nanofluid was evaluated based on various attributes using the weighted sum model (WSM) method, and the rank - ing of nanofluids was given. To begin, water served as the medium for free convection heat transfer experiments to validate the experimental setup. Free convection heat transfer experiments were carried out using metal oxide-based water nanofluids as mediums at volume fractions ranging from 0% to 1% for various heat inputs in the range of 30 W and 50 W. The heat transfer coefficient augments with percentage volume concentration up to 0.1 % for all types of nanofluids and then decreases until it reaches 0.6% volume fraction. Al 2 O 3 -water nanofluid performs better than other metal oxide nanofluids in both WSM and experimental methods.

  • Artificial Neural Network Technique for Estimating the Thermo-Physical Properties of Water-Alumina Nanofluid
    Sajja Ravi Babu, K.P.V. Krishna Varma, and Kunapuli Siva Satya Mohan
    Wydawnictwo Naukowe Gabriel Borowski (WNGB)
    With its superior thermo-physical characteristics to the carrier fluid, nanofluid is the most impactful heat transfer fluid. Thermal conductivity, density, viscosity, specific heat, coefficient of volumetric expansion, and other thermophysical parameters play an important part in the thermal management of any heat transfer application. This thermal management governs the service life of an equipment or apparatus, which dissipates heat during its operation. If the equipment is well-managed thermally, then its service life will be extended. Otherwise the equipment stops functioning due to excess heat. Thermo-physical properties of nanofluid vary with the change in the concentration of nanoparticles. Estimation of the properties with the varying concentrations of the nanoparticles is time consuming and is economically not viable. There were many empirical models available in the literature for determining the thermo-physical properties of nanofluids. However, each model provides different values of thermo-physical properties and choosing the best model among the models available is a complex task. In this regard, to avoid the complication in choosing the best model, and in order to envisage the thermo-physical properties of the nanofluid, the Artificial Neural Network (ANN) technique was used. This technique is widely used among the researchers for various applications. The ANN approach was utilized in this work to estimate viscosity and thermal conductivity of water-based Al2O3 nanofluid for volume fractions between 0.01% and 0.1%. For thermal conductivity, mean square error (MSE) was observed as 4.504e-09 and for viscosity, it was observed as 6.4742e-09. Training times were 5 seconds and 4 seconds for thermal conductivity and viscosity datasets, respectively.

  • Recent developments in synthesis, characterization and boiling heat transfer of nanofluids - A Review
    S Ravi Babu, A Saras Chandra, and P Ramesh Babu
    IOP Publishing
    Abstract The life of a thermal system depends on how effectively the heat (which is released during its operation), being transferred. Selection of the right fluid is imperative in providing the heat transfer solution for a particular thermal system. Nanofluids are the new generation heat transfer fluids which will give better performance with their superior thermos-physical properties. So much research has been done on nanofluids during the recent years on several aspects like synthesizing the stable nanofluids without losing their properties, characterization, application of nanofluids to forced convection, free convection, boiling heat transfer. The present review is concentrated mainly on the experimental investigations on the preparation and characterization of nanofluids and its applications in several areas. Majority of studies reported that critical heat flux improves with the nanofluids. It will be very useful for the researchers who are about to work on the nanofluids.

  • Effect of moisture and sonication time on dielectric strength and heat transfer performance of transformer oil based Al<inf>2</inf>O<inf>3</inf> nanofluid
    S. Ravi Babu, N.V.A Ravi Kumar, and P. Ramesh Babu
    Association of Computer, Communication and Education for National Triumph Social and Welfare Society (ACCENTS)
    1.Introduction Power transformer’s role is very much critical in the transmission and distribution of electricity to the consumers from power stations. The insulating liquid is crucial to the performance of the transformer [1]. Transformers expose to various stresses like thermal, electric, and chemical during their operation. Periodical checkups and maintenance of insulating oil in the transformer are very much required to prevent sudden failure [2]. One of the most detrimental elements to transform paper and oil insulation is moisture. It weakens the dielectric and lowers the Partial Discharge (PD) inception voltage, affects the electrical characteristics [3]. Aging and external causes are the two most important variables that encourage moisture intrusion in transformers. The moisture equilibrium characteristics of oil and paper insulation are well-known and broadly applied to estimate how much moisture is involved.

  • Experimental investigation of free connective heat transfer augmentation using transformer oil-Al<inf>2</inf>O<inf>3</inf>nanofluid
    S Ravi Babu, A Saras Chandra, and P Ramesh Babu
    IOP Publishing
    There is a definite need to improve the heat transfer capability of the transformer oil as it plays a vital role in the life span of transformers. As the thermal conductivity of the transformer oil is very less compared to the conventional liquids and those liquids cannot be used as dielectric liquids as they do not possess electrical insulation properties. It is very much essential to improve the thermal conductivity of the transformer oil in any manner in order to augment the “heat transfer or thermal management performance” of the transformer oil. Dispersion of metallic or metallic oxide nanoparticles into the base fluid in a systematic way is a proven method to enhance the thermal properties for various practical heat transfer applications like forced convection, boiling, refrigeration, solar and electronic cooling. In this study, alumina nanoparticles are dispersed in transformer oil to synthesize stable, homogenous transformer oil – Al2O3 nanofluid and to investigate the free convection “coefficient of heat transfer performance” along a vertical slender cylinder submerged in the liquid. Experiments are conducted using the transformer oil - Al2O3 nanofluid at different particle loadings or fractions starting from 0.05 % to 0.6 %. It is learnt that the highest “coefficient of heat transfer performance” occurs at 0.1 Vol% among all the volume fractions. It has been acknowledged that the “coefficient of heat transfer” is got better up to 0.1 % particle loading and then decreased with additional accumulation of nanoparticles.

  • Experimental investigation of radiator heat transfer efficiency using Water + Ethylene Glycol based Al<inf>2</inf>O<inf>3</inf>, SiC nanofluids
    S. SatyaPrasad, V. Rambabu, and S. Ravibabu
    IOP Publishing
    Abstract The experimental work to boost forced heat transfer performance in an Al2O3, SiC-Water+ ethylene glycol nanofluid radiator was discussed in this paper. In this analysis, different volume fractions of nanofluids in the range of 0.01 to 0.1 percent were prepared and sonicated for 2 hours using an ultrasonic sonicator to achieve stable suspension with the incorporation of Al2O3, Sic nanoparticles into the water. The maxium-performable heat transfer was found to be 50 percent higher than water at a fraction of 0.1 per cent. The effective thermal conductivity of the nanofluid is increased with increased particle concentration, which helps to boost radiator heating efficiency. The rate of heat flow ranges from 3 to 12 lpm. It is noted that the efficiency of heat transfer has increased with an increase in flow rate.

  • Experimental investigation on natural convection heat transfer augmentation with vibration effect by using water-al2o3 nanofluid


  • Buoyancy-induced natural convective heat transfer along a vertical cylinder using Water-Al<inf>2</inf>O<inf>3</inf> nanofluids
    S. Ravi Babu and G. Sambasiva Rao
    ASME International
    Buoyancy-induced natural convective heat transfer along a vertical cylinder immersed in Water–Al2O3 nanofluids for various concentrations (0, 0.05, 0.1, 0.2, 0.4, 0.6 vol %) under constant heat flux condition was investigated experimentally and presented. Thermal stratification was observed outside the boundary layer in the ambient fluid after steady-state condition is achieved as the fluid temperature goes on increasing along the axial direction. Temperature variations of the cylinder along the axial direction and temperature variations of fluid in radial direction are shown graphically. It is observed that the temperatures of the cylinder and the fluid increases along the axial direction and the fluid temperature decreases in the radial direction. Experiments were conducted for various heat inputs (30 W, 40 W, 45 W, and 50 W) and volume concentrations and observed that the addition of alumina nanoparticles up to 0.1 vol % enhances the thermal performance and then the further addition of nanoparticles leads to deterioration. The maximum enhancement in the natural convection heat transfer performance is observed as 13.8%, i.e., heat transfer coefficient is increased from 382 W/m2 K to 435 W/m2 K at 0.1 vol % particle loading.

  • Experimental investigation on stability and dielectric break down strength of transformer oil based nanofluids
    Ravi Babu S. and Sambasiva Rao G.
    Author(s)
    The main objective of this study is to investigate the stability and dielectric breakdown strength of alumina-transformer oil nanofluids as stability issue is the major concern when it is used for practical applications. UV-Vis spectrophotometer and Oil tester were used to measure absorbance and breakdown voltage of nanofluids respectively. As per the experimental results, correlations were developed using regression analysis. Experimental results were compared with the predicted values of BDVE and absorbance and presented. The maximum errors obtained by comparing the experimental and predicted results for BDVE and absorbance are -2.913% and 4.89% respectively. It is also observed that there is a decrement in both BDVE and absorbance for nanofluids of aged 1 day compared to fresh ones. This decrement is due to the sedimentation of nanoparticles.


  • Thermal conductivity and viscosity of water and ethylene glycol blend based alumina Nanofluids - An experimental study
    Ravi Babu. S et al., Ravi Babu. S et al., and
    Transstellar Journal Publications and Research Consultancy Private Limited

  • Enhancement of heat transfer in shell and tube heat exchanger by using nano fluid
    V Rambabu et al., V Rambabu et al., and
    Transstellar Journal Publications and Research Consultancy Private Limited
    Heat transfer rate of TiO2 and water Nano fluids were measured in a shell and tube heat exchanger under the turbulent flow condition. Even with insignificant focus of Nano particles in the base fluids, results in enhancement of heat transfer coefficient. Heat transfer rate of TiO2, at its optimum Nano particle concentration are greater than the water particle. From the past research, it is evident that, the addition of Nano particles increases the heat transfer rate. So for the present study, TiO2Nanoparticles were chosen for dispersing them in the water, for enhancing heat transfer properties and comparing them with only pure base fluid. The current study is also extended to find the overall heat transfer coefficient and the amount of heat transfer enhancement at different flow rates. Further, heat transfer characteristics like Reynolds number and effectiveness were also measured. From the experimental outcomes, it is observed that, there is a clear enhancement in the heat transfer characteristics with addition of Nano particle, at different volume concentrations (0.05%, 0.1%, 0.15% and 0.2%), for different flow rates.

  • Experimental investigation of natural convective heat transfer using water-Alumina nanofluid with taguchi design of experiments


RECENT SCHOLAR PUBLICATIONS

  • Formative Learning Through a Spatial Visualization-Based Cadathon Contest
    GVSS Sharma, AL Naidu, K Santarao, BV Suresh, P Kumar, Y Shireesha, ...
    Journal of Formative Design in Learning, 1-16 2024

  • Effect of Inclination and Thermoelectric Material on the Performance of Solar PV-Thermo Electric Cooling System
    SR Babu, SA Basha, G Sasikumar, PP Kumar
    Ecological Engineering & Environmental Technology 25 2024

  • Bridging the industry–academia gap: An experiential learning for engineering students
    GVSS Sharma, AL Naidu, KS Rao, BV Suresh, P Kumar, Y Shireesha, ...
    Journal of Formative Design in Learning 7 (2), 139-157 2023

  • Wear Analysis of Iron Slag Reinforced Polyester Composites with Taguchi Optimization.
    NV Kumar, SA Basha, CC Kishore, P Aswarthanarayana, PP Kumar, ...
    Ecological Engineering & Environmental Technology (EEET) 24 (6) 2023

  • Nanofluid selection for an automobile radiator using weighted sum model technique
    SR Babu, KPV Varma, PR Babu
    AIP Conference Proceedings 2548 (1) 2023

  • Experimental investigation on free convective heat transfer performance of oxide nanofluids along a vertical cylinder
    S Ravi Babu, KP Pradeep, SA Basha, RM Maruthi
    Ecological Engineering & Environmental Technology 24 2023

  • Artificial neural network technique for estimating the thermo-physical properties of water-alumina nanofluid
    S Ravi Babu, KPV Krishna Varma, KSS Mohan
    Ecological Engineering & Environmental Technology 23 2022

  • Effect of moisture and sonication time on dielectric strength and heat transfer performance of transformer oil based Al2O3 nanofluid
    SR Babu, NVAR Kumar, PR Babu
    International Journal of Advanced Technology and Engineering Exploration 8 2021

  • Recent developments in synthesis, characterization and boiling heat transfer of nanofluids–A Review
    SR Babu, AS Chandra, PR Babu
    IOP Conference Series: Materials Science and Engineering 1033 (1), 012072 2021

  • Experimental investigation of free connective heat transfer augmentation using transformer oil-Al2O3 nanofluid
    SR Babu, AS Chandra, PR Babu
    IOP Conference Series: Materials Science and Engineering 998 (1), 012022 2020

  • Comparative Analysis of Stability and Dielectric Break Down Strength of Transformer Oil Based Nanofluids
    SR Babu, PR Babu
    Int. J. Electr. Eng. Technol.(IJEET) 11 (5) 2020

  • Selection of a four wheel passenger car using AHP and TOPSIS approach—Indian Scenario
    SR Babu, V Manoj
    Int J Adv Sci Technol 29 (6), 5542-5548 2020

  • Experimental investigation of natural connective heat transfer augmentation with vibration effect
    SRB B.Sudhakar rao
    International Research Journal of Engineering and technology 6 (8), 1496-1503 2019

  • A case series of neuroendocrine carcinoma of the stomach
    RV Rao, S Brahamjit, S Babu
    J Med Sci Res 7 (2), 25-31 2019

  • Thermo-physical Properties of Water +Ethylene Glycol based Alumina Nanofluids
    GSR S.Ravi Babu
    Journal of Mechanical Engineering Research and Developments 41 (1), 168-176 2018

  • Experimental Investigation on Stability and Dielectric Break Down Strength of Transformer Oil Based Nanofluids
    GSR S.Ravi Babu
    International Conference on Electrical, Electronics, Materials and Applied 2018

  • Buoyancy Induced Natural Convective Heat Transfer along a Vertical Cylinder using Water/Al2O3 nanofluids
    RB Sajja
    Journal of Thermal Science and Engineering Applications 10 (3) 2018

  • Stability Analysis of Aquatic Alumina Nanofluid using TAGUCHI Design of Experiments
    GSR S.Ravi Babu
    New Frontiers in Engineering, Science & Technology (NFEST-2018), 814-818 2018

  • Experimental investigation on natural convection heat transfer enhancement using transformer oil-TiO2 nanofluid
    MR Kiran, SR Babu
    IRJET 5 (7), 1412-1418 2018

  • ENHANCEMENT OF HEAT TRANSFER IN SHELL AND TUBE HEAT EXCHANGER BY USING NANO FLUID
    SRB V.Rambabu, J.Ramarao
    International Journal of Mechanical and Production Engineering Research and 2017

MOST CITED SCHOLAR PUBLICATIONS

  • Effects of some parameters on thermal conductivity of nanofluids and mechanisms of heat transfer improvement
    SR Babu, PR Babu, V Rambabu
    Int. J. Eng. Res. Appl 3 (4), 2136-2140 2013
    Citations: 22

  • ENHANCEMENT OF HEAT TRANSFER IN SHELL AND TUBE HEAT EXCHANGER BY USING NANO FLUID
    SRB V.Rambabu, J.Ramarao
    International Journal of Mechanical and Production Engineering Research and 2017
    Citations: 14

  • Artificial neural network technique for estimating the thermo-physical properties of water-alumina nanofluid
    S Ravi Babu, KPV Krishna Varma, KSS Mohan
    Ecological Engineering & Environmental Technology 23 2022
    Citations: 11

  • EXPERIMENTAL INVESTIGATION OF NATURAL CONVECTIVE HEAT TRANSFER USING WATER-ALUMINA NANOFLUID WITH TAGUCHI DESIGN OF EXPERIMENTS
    GSR S.Ravi Babu
    International Journal of Mechanical Engineering and Technology (IJMET) 8 (7 2017
    Citations: 11

  • Experimental investigation on natural convection heat transfer enhancement using transformer oil-TiO2 nanofluid
    MR Kiran, SR Babu
    IRJET 5 (7), 1412-1418 2018
    Citations: 9

  • Buoyancy Induced Natural Convective Heat Transfer along a Vertical Cylinder using Water/Al2O3 nanofluids
    RB Sajja
    Journal of Thermal Science and Engineering Applications 10 (3) 2018
    Citations: 8

  • Experimental investigation of free connective heat transfer augmentation using transformer oil-Al2O3 nanofluid
    SR Babu, AS Chandra, PR Babu
    IOP Conference Series: Materials Science and Engineering 998 (1), 012022 2020
    Citations: 5

  • Experimental investigation of natural connective heat transfer augmentation with vibration effect
    SRB B.Sudhakar rao
    International Research Journal of Engineering and technology 6 (8), 1496-1503 2019
    Citations: 5

  • Thermo-physical Properties of Water +Ethylene Glycol based Alumina Nanofluids
    GSR S.Ravi Babu
    Journal of Mechanical Engineering Research and Developments 41 (1), 168-176 2018
    Citations: 4

  • Bridging the industry–academia gap: An experiential learning for engineering students
    GVSS Sharma, AL Naidu, KS Rao, BV Suresh, P Kumar, Y Shireesha, ...
    Journal of Formative Design in Learning 7 (2), 139-157 2023
    Citations: 3

  • Effect of moisture and sonication time on dielectric strength and heat transfer performance of transformer oil based Al2O3 nanofluid
    SR Babu, NVAR Kumar, PR Babu
    International Journal of Advanced Technology and Engineering Exploration 8 2021
    Citations: 3

  • Recent developments in synthesis, characterization and boiling heat transfer of nanofluids–A Review
    SR Babu, AS Chandra, PR Babu
    IOP Conference Series: Materials Science and Engineering 1033 (1), 012072 2021
    Citations: 3

  • Radiation effects on MHD boundary layer flow of a nanofluid past an exponential permeable stretching sheet embedded in a porous medium
    M Lavanya, S Babu, RGM Venkata, S Suneetha
    Asian Journal of Science and Technology 7 (4), 2815-2824 2016
    Citations: 3

  • Wear Analysis of Iron Slag Reinforced Polyester Composites with Taguchi Optimization.
    NV Kumar, SA Basha, CC Kishore, P Aswarthanarayana, PP Kumar, ...
    Ecological Engineering & Environmental Technology (EEET) 24 (6) 2023
    Citations: 2

  • Nanofluid selection for an automobile radiator using weighted sum model technique
    SR Babu, KPV Varma, PR Babu
    AIP Conference Proceedings 2548 (1) 2023
    Citations: 2

  • Experimental investigation on free convective heat transfer performance of oxide nanofluids along a vertical cylinder
    S Ravi Babu, KP Pradeep, SA Basha, RM Maruthi
    Ecological Engineering & Environmental Technology 24 2023
    Citations: 2

  • Comparative Analysis of Stability and Dielectric Break Down Strength of Transformer Oil Based Nanofluids
    SR Babu, PR Babu
    Int. J. Electr. Eng. Technol.(IJEET) 11 (5) 2020
    Citations: 2

  • Selection of a four wheel passenger car using AHP and TOPSIS approach—Indian Scenario
    SR Babu, V Manoj
    Int J Adv Sci Technol 29 (6), 5542-5548 2020
    Citations: 2

  • Experimental investigation of cooling performance of an Automobile radiator using Al2O3-Water+ethylene Glycol nanofluid
    SRB D.Tirupathi rao
    International Journal of Engineering Research and Development 11 (07), 28-35 2015
    Citations: 2

  • PERFORMANCE AND COMBUSTION CHARACTERISTICS OF DI-DIESEL ENGINE USING NEAT MME WITH DEE
    SR P.Ramesh Babu, Dr.V.Rambabu
    International Journal of Emerging Technology and Advanced Engineering 3 (3 2013
    Citations: 2