Qualification: 
Ph.D, M.Tech, B-Tech
r_kannan@cb.amrita.edu

Dr. R. Kannan currently serves as Assistant Professor (SG) at the department of Aerospace Engineering, School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore Campus.

Kannan ‘s research focuses on the harness the effect due to the interaction of the fluid flow with micro and nanostructured asperities present solid surfaces for various engineering applications such as Liquid Atomization,  Biologically Inspired Anti-icing Surfaces, Thermal Barrier Coating, Corrosion Control, etc. In addition to this, focus on the development of ultra light weight highly efficient combustor for Gas Turbine Combustor, Afterburner, Ramjet, and Scramjet Engine.

Prior to starting his career as Assistant Professor (SG) at Amrita on 2016, he was with the University of Toronto, Canada (2011 – 2013) as a Post-Doctoral Fellow. He received his Ph. D in Aerospace Engineering from Indian Institute of Science (IISc. 2012) Bangalore after studying his M. Tech in Aerospace Engineering from Indian Institute of Technology (IIT, 2002) Kanpur and B. Tech in Aeronautical Engineering (2000) from Madras Institute of Technology, Anna University Chennai. He is currently supervising one research student for the award of the Ph. D degree. His teaching interest is in the field of High-Speed Flows, Propulsion, and Combustion.

His research interests include Atomization and Characterization of liquid jets and sprays, Biologically inspired Anti-icing and self-cleaning surfaces, Extraction of Bio-oil and Bio-gas from Biomass Composite, Corrosion Control using Superhydrophobic Surfaces, New Combustor Technology Development for Gas Turbine, Afterburner, Ramjet, and Scramjet.

Funded Projects

  • Impact of Surface Micro-Structure modification using Plasma Process and its Wetting Behavior on the Corrosive Nature of Stainless Steel Surfaces funded by BRNS – PFRC (PI).

Publications

Publication Type: Conference Proceedings

Year of Publication Title

2018

R. K. Sekar, Jegadheeswaran, S., Dr. R. Kannan, Vadivelu, P., and Prasad, G., “Numerical investigation of single ramp scramjet inlet characteristics at mach number 5.96 due to shock Wave–Boundary layer interaction”, 3rd International Conference on Innovative Design and Development Practices in Aerospace and Automotive Engineering (IDAD2018) . Pleiades Publishing, pp. 181-186, 2018.[Abstract]


A single ramp scramjet inlet is designed for operating at a Mach number of 5.96 and studied for subsonic bubble formation due to the shock wave–boundary layer interaction (SWBL). The Navier–Stokes computational fluid dynamics equation for ideal gas condition, with two-equation k–ω shear stress transport (SST) turbulence model, is solved using the RANS solver. The inlet designed with a ramp of 38.7° generates a strong shock wave made to impinge on the cowl generates a large separation bubble. The results obtained are validated with experimental results. Further, the inlet flow characteristics are analyzed under the unsteady condition to study the motion of the shock wave, variation of subsonic bubble size, the wall surface pressure fluctuation, and effect on mass flow due to the bubble size variation. Due to the shock wave–boundary layer interaction, the mass flow rate becomes unsteady in the core flow zone of the inlet. © Springer Nature Singapore Pte Ltd. 2019.

More »»

2007

Dr. R. Kannan and Deivandren, S., “Drop Impact on a Solid Surface Comprising Micro Groove Structure”, Fourth International Conference on Flow Dynamics (ICFD2007), vol. AIP Conference Proceedings. Sendai International Conference Center, Japan, 2007.[Abstract]


Spreading and receding processes of water drops impacting on a stainless steel surface comprising rectangular shaped parallel grooves are studied experimentally. The study was confined to the impact of drops in inertia dominated flow regime with Weber number in the range 15-257. Measurements of spreading drop diameter and drop height were obtained during the impact process as function of time. Experimental measurements of spreading drop diameter and drop height obtained for the grooved surface were compared with those obtained for a smooth surface to elucidate the influence of surface grooves on the impact process. The grooves definitely influence both spreading and receding processes of impacting liquid drops. A more striking observation from this study is that the receding process of impacting liquid drops is dramatically changed by the groove structure for all droplet Weber number.

More »»

Publication Type: Conference Paper

Year of Publication Title

2017

Dr. R. Kannan, Annakodi, V., Vasudevan, H., Singh, A., and Jayalakshmi, S., “Effect of Cashew Nut Shell Oil (Cardanol) on Water Absorption and Mechanical Characteristics of Sisal Fibers”, in Proceedings of the International Conference on Recent Innovations in Production Engineering (RIPE), At Madras Institute of Technology (MIT), Anna University, Chennai-600044, India, 2017.[Abstract]


Polymer matrix composites (PMCs) are light weight and have high strength to weight ratio, owing to which they are attractive for aviation and automotive industries. Amongst PMCs, glass fiberepoxy composites are being widely used. Replacement of synthetic materials by naturally available materials (i.e. agricultural products) as fiber and/or resin in making composites will ensure bio-degradability and eco-friendliness. In the view of developing natural fiber reinforced composites, in this work sisal fibers treated with/without cardanol oil have been investigated for their water absorption and strength characteristics. The investigation revealed that when compared to the untreated fibers, the cardanol treated fibers exhibit (i) 35 % reduction in water absorption and (ii) increased tensile strength property.

More »»

2016

Dr. R. Kannan, Annakodi, V., Arumugam, V., R, N., Kumar, K., Mylasamy, S., and Praveenkumar, G., “Strength Enhancement of Sisal Fibre by its Wettability Modification with Cardanol”, in International Conference on Materials Science & Technology 2016, University of Delh, 2016.[Abstract]


The dependency of fossil fuel sources for the manufacturing of composites from the artificial fibres and resins warrants the search for alternative renewable sources of raw materials for the composites. Because of the fibres and resins from the renewable source of materials, the cost of the composite materials is going to reduce and also reduces the foreign exchange that is going to be paid towards the procurement of raw materials based on the fossil fuel sources. Comparing to the conventional artificial composite materials, the natural composite materials from the renewable agricultural sources are environment friendly. Even though, there is enough sources for the production of natural fibres and resins from different plant sources, sisal fibres are seems to be better in the terms of cost, availability, strength and the resin synthesized cashew nut shell oil are available in abundant amount in a lower cost with better physico-chemical properties. The goal of the present work is to optimize the strength of sisal fibre by using novolac resin. The sisal fibre has inherent characters of having lots of porous holes connected through lumens. Because of this porous structure, the strength of the fibre is less when compared to artificial fibres and also has higher water absorption tendency when it is subjected to humid environment. In addition to this, the water absorption behaviour associated with chemical nature and porous physical structures results in reduction of strength of the fibres, in turn the strength of the composites. In order to address these issues, the chemical group present in the resin matrices has to be transferred to the internal and external surfaces of the fibre walls. The resin was prepared from the cardanol oil and it is hydrophobic in nature. Because of this hydrophobic behaviour and similar chemical group, the fibres are treated with cardanol oil for different period of time with two different environmental conditions such as hot and cold. The strength of the fibres are measured with single fibre and bunch of fibres mode using Instron and Magisoft UTM fibre testing machine respectively. The raw untreated fibres result in lower strength than the cold and hot environmental conditions treated sisal fibres. Even specifically, the prolonged treatment of sisal fibres in a cold environment yields better strength than the fibres treated in the hot environmental conditions. Further, the water absorption characteristics of cold treated sisal fibres are reduced so drastically to the value of 50% (approx.) from 90% (approx.) for untreated fibres. The hot treated fibres have a less value of water absoption behavior than untreated one, but have a higher water absorption rate than cold treated fibres. The internal structure of the fibres was examined with the help of Scanning Electron Microscope (SEM, Zeiss). Images show variation in the internal structure between the untreated and the cold treated fibres. Because of the treatment with cardanol oil, the non-wetting behaviour of the fibre increased which helps in reducing the water absorption characteristics.

More »»

2015

R. Karuppusamy, Jegadheeswaran, S., Dr. R. Kannan, Madhan, M., Seethapathi, M., and Prasanth, R., “Active Control of Separation Bubble formed due to Shock Wave - Boundary Layer Interaction in the Supersonic / Hypersonic Intake”, in 7th Symposium on Applied Aerodynamics And Design of Aerospace Vehicles (SAROD-2015), VSSC, ISRO, Trivandrum, 2015.[Abstract]


An active control method was numerically simulated using Fluent and Gambit commercial CFD package for controlling the size of the subsonic separation bubble caused due to the interaction of oblique shock and turbulent boundary layer. The physical domain was designed for investigating the effect of porosity on the different locations in and around the subsonic separation bubble. The size of bubble was reduced by considerable amount for the physical domain with porous holes in both upstream and downstream of the separation bubble location. This phenomenon mainly occurred due to the establishment of a fluid flow feedback loop between the upstream and downstream of the bubble through porosity on those solid walls.

More »»

2009

Dr. R. Kannan, Vaikuntanathan, V., and .Sivakumar, D., “Final Spreading Characteristics of Liquid Droplets Impacting on Groove-Textured Surfaces”, in Conference and Exhibition in Aerospace Engineering (ICEAE 2009), Indian Institute of Science, Bangalore, India, 2009.

2009

V. Vaikuntanathan, Dr. R. Kannan, and Deivandren, S., “Droplet Transport on a Discrete Wettability Gradient Surface: Role of Droplet Weber Number”, in International Conference on Liquid Atomization and Spray Systems (ICLASS), Vail, Colorado, US, 2009.[Abstract]


Understanding droplet motion on wettability gradient surfaces has received considerable academic interest in the context of controlled motion of droplet liquid in a specified direction in micro-scale devices such as biochips. The present work deals with the impact of water droplets of low Weber number (We) onto solid surfaces comprising of a discrete gradient of roughness (and hence wettability). Two stainless steel solid surfaces – TGS1 and TGS2 – each comprising of a smooth and a parallel groove-textured portion and differing only in the geometry of the textured portion were used. Water droplets of diameter ~ 2.6 mm were impacted onto the interface of the roughness gradient from different heights simulating different We. Bulk droplet motion perpendicular to the groove direction was con-sidered. The outcomes of the droplet impact experiments were elucidated in terms of factors significant from the point-of-view of droplet transport: (1) the final horizontal distance moved by the droplet from the impact point, (2) the final contact diameter of the droplet, (3) receding intensity of the droplet fronts on either sides of the interface, and (4) amplitude of droplet oscillations at the final stage of droplet transport. With an increase in impact We all the above-mentioned droplet transport parameters deteriorated for both the surfaces indicating a less efficient droplet transport at higher impact Weber numbers. This can be understood qualitatively via energy considerations. More-over, for a given impact condition, the droplet transport parameters were found to be superior in the case of TGS2 surface. Attempts were made to explain this behavior in terms of the relative magnitude of wettability gradient (or the difference between the equilibrium contact angles of water on smooth and textured portions) and contact angle hysteresis on these solid surfaces.

More »»

2008

Dr. R. Kannan and Deivandren, S., “Spreading and Receding Processes of Impacting Liquid Drops on Grooved Surfaces”, in 22nd European Conference on Liquid Atomization and Spray Systems (ILASS2008),, Como Lake, Italy, 2008.

Publication Type: Journal Article

Year of Publication Title

2017

V. Annakodi, Arumugam, V., and Dr. R. Kannan, “Static Wetting Characteristics of Micro-textured Stainless Steel Surfaces under Uniaxial Loading Condition”, International Journal of Surface Science and Engineering, vol. 11, p. 174, 2017.[Abstract]


The wetting behaviour associated with the surface micro asperities is investigated on the groove and pillar textured SS304 solid surface which is widely used in the flight vehicles where the stresses are induced by uniaxial compressive loads for both positive and negative curvature. By varying the applied load on the groove-textured surfaces in the direction perpendicular to grooves, the positive curvature shows a decrease in static contact angle initially then increases for further increase in deflection; however, the negative curvature induced by the same applied load shows an opposite trend. At the same time, in the pillar-textured surface, the static contact angle decreases with increase in applied load for the positive curvature and the same wetting parameter shows an opposite trend for the negative curvature. This phenomenon is mainly attributed to the pinning behaviour of the three phase contact line of the liquid drop on these two surfaces.

More »»

2017

V. Vaikuntanathan, Dr. R. Kannan, and Sivakumar, D., “An experimental study on the equilibrium shape of water drops impacted on groove-textured surfaces”, Experimental Thermal and Fluid Science, vol. 87, pp. 129-140, 2017.[Abstract]


Understanding the final shape of liquid drops deposited on groove-textured surfaces is a significant aspect of many applications (for example, liquid drainage). This is lacking in literature, especially for drop impact on micro-textured surfaces. The effect of drop impact velocity and groove-texture geometry on the final shape adopted by water drops impacted on groove-textured surfaces is reported here. Water drops gently placed on groove-textured surfaces comprising trapezoidal (rectangular) pillars adopted the Wenzel (Cassie) state. Top view images of final equilibrium shape of water drops impacted on the groove-textured surfaces revealed a contrasting behavior between Wenzel and Cassie surfaces. At low impact velocity, the final drop shape on Wenzel surface is elongated more in the direction parallel to the grooves than perpendicular to grooves thereby exhibiting anisotropy whereas on Cassie surface the final drop shape is almost isotropic. As impact velocity increases, the anisotropy in final drop shape on Wenzel surface decreases whereas on Cassie surface it increases. The final drop spread factors and contact angles measured perpendicular and parallel to grooves show contrasting trends with impact velocity between Wenzel and Cassie surfaces. This is modelled through the difference between drop receding perpendicular and parallel to the grooves, resulting from a difference in liquid drop impregnation state, between the surfaces. © 2017 Elsevier Inc.

More »»

2011

Dr. R. Kannan, Vaikuntanathan, V., and Sivakumar, D., “Dynamic Contact Angle Beating From Drops Impacting onto Solid Surfaces Exhibiting Anisotropic Wetting”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 386, no. 1-3, pp. 36 - 44, 2011.[Abstract]


This paper reports an experimental investigation of low Weber number water drops impacting onto solid surfaces exhibiting anisotropic wetting. The wetting anisotropy is created by patterning the solid surfaces with unidirectional parallel grooves. Temporal measurements of impacting drop parameters such as drop base contact diameter, apparent contact angle of drop, and drop height at the center are obtained from high-speed video recordings of drop impacts. The study shows that the impact of low Weber number water drops on the grooved surface exhibits beating phenomenon in the temporal variations of the dynamic contact angle anisotropy and drop height at the center of the impacting drop. It is observed that the beating phenomenon of impacting drop parameters is caused by the frequency difference between the dynamic contact angle oscillations of impacting drop liquid oriented perpendicular and parallel to the direction of grooves on the grooved surface. The primary trigger for the phenomenon is the existence of non-axisymmetric drop flow on the grooved surface featuring pinned and free motions of drop liquid in the directions perpendicular and parallel to the grooves, respectively. The beat frequency is almost independent of the impact drop Weber number. Further experimental measurements with solid surfaces of different groove textures show that the grooved surface with larger wetting anisotropy may be expected to show a dominant beating phenomenon. The phenomenon is gradually damped out with time and is fully unrecognizable at higher drop impact Weber numbers.

More »»

2010

V. Vaikuntanathan, Dr. R. Kannan, and Deivandren, S., “Impact of Water Drops onto the Interface of a Hydrophobic Texture and a Hydrophilic Smooth Surfaces”, Colloids and Surfaces A-physicochemical and Engineering Aspects - COLLOID SURFACE A, vol. 369, pp. 65-74, 2010.[Abstract]


Wettability gradient surfaces play a significant role in control and manipulation of liquid drops. The present work deals with the analysis of water drops impacting onto the junction line between hydrophobic texture and hydrophilic smooth portions of a dual-textured substrate made using stainless steel material. The hydrophobic textured portion of the substrate comprised of unidirectional parallel groove-like and pillar-like structures of uniform dimensions. A high-speed video camera recorded the spreading and receding dynamics of impacting drops. The drop impact dynamics during the early inertia driven impact regime remains unaffected by the dual-texture feature of the substrate. A larger retraction speed of drop liquid observed on the hydrophobic portion of the substrate during the impact of low velocity drops makes the drop liquid on the higher wettability portion to advance further (secondary drop spreading). The net horizontal drop velocity towards the hydrophilic portion of the dual-textured substrate decreases with increasing drop impact velocity. The available experimental results suggest that the movement of bulk drop liquid away from the impact point during drop impact on the dual-textured substrate is larger for the impact of low inertia drops

More »»

2008

Dr. R. Kannan and Sivakumar, D., “Drop Impact Process on a Hydrophobic Grooved Surface”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 317, pp. 694 - 704, 2008.[Abstract]


The impact of water drops on a grooved surface exhibiting hydrophobic features is studied experimentally. The grooved surface is made of stainless steel and is comprised of a structure of unidirectional grooves. The groove structure yielded contact angles 135° and 107° for water on the surface perpendicular to the groove direction and parallel to the groove direction respectively compared to 80° on a smooth stainless steel surface. The influence of groove structure on the drop impact process is studied by comparing the experimental results of drop impact on the grooved surface with those obtained for the smooth surface. The groove structure alters the shape of the liquid lamella spreading on the grooved surface. For the impact of high inertia drops on the grooved surface, the droplet liquid flowing inside the grooves ejects out as tiny droplets during early stages of the impact. On the grooved surface, the impacting drop spreads along the groove direction in a similar manner as observed on the smooth surface, and the solid pillars of the grooved surface hinder the spreading of droplet liquid perpendicular to the groove direction. The enhanced hydrophobicity of the grooved surface makes the droplet liquid to rebound more intensely than that on the smooth surface.

More »»

2008

Dr. R. Kannan and Sivakumar, D., “Impact of Liquid Drops on a Rough Surface Comprising Microgrooves”, Experiments in Fluids, vol. 44, pp. 927–938, 2008.[Abstract]


Impact of water drops on a stainless steel surface comprising rectangular shaped parallel grooves is studied experimentally. Geometric parameters of the surface groove structure such as groove depth, groove width and solid pillar width separating any two successive grooves were kept at 7.5, 136 and 66 μm, respectively. The study was confined to the impact of drops in inertia dominated flow regime with Weber number in the range 15–257. Experimental results of drop impact process obtained for the grooved surface were compared with those obtained for a smooth surface to elucidate the influence of surface grooves on the impact process. The grooves definitely influence both spreading and receding processes of impacting liquid drops. A more striking observation from this study is that the receding process of impacting liquid drops is dramatically changed by the groove structure for all droplet Weber number.

More »»

2004

Dr. R. Kannan and Mishra, D., “An Experimental Study of Lean Premixed Swirl Combustor”, International Journal of Turbo and Jet Engines, vol. 21, pp. 103-113, 2004.

2003

Dr. R. Kannan and Mishra, D., “An Experimental Study of Lean Premixed Combustor”, International Journal of Turbo and Jet Engines, vol. 20, pp. 245-253, 2003.[Abstract]


The combustion processes involved in the lean premixed combustor are studied with help of coaxial burner using bluff body flame holder. The lean stability and emission analysis are investigated in details for two flame holder locations, H/Dcore = 0.61 and 5.0. The lean flame stability limits are measured for a wide range core velocity of 4-20 m/s. The lean stability limits for coflow air stream are improved for H/Dcore = 5. 0 due to the improved mixing of coflow with core flow streams. But there is an increase of the NO emission for H/Dcore = 5.0, which may be due to higher combustion gas temperature. On the contrary, the CO emission level is reduced considerably, which may be attributed to the presence of excess coflow air. In order to reduce the emission level, the partially premixed fuel-air mixture is injected in the coflow stream instead of air. The stability limit is improved marginally for H/Dcore = 5.0 when the premixed mixture is used in the coflow stream. Interestingly, this partially premixed fuel injection in the coflow stream although reduces the NO emission level, but produces little more CO emission. It is believed that these findings will be helpful in designing and developing lean premixed flame based combustor in future.

More »»