Article
Chemistry, Physical
A. C. Rajesh, S. Jeyakumar, Kandasamy Jayaraman, Mehmet Karaca
Summary: This study investigates the flow performance of a dual wall-mounted cavities in a strut-injector mounted scramjet combustor under steady-state and transient reacting conditions. The research compares two-dimensional Reynolds Averaged Navier-Stokes approach and Delayed Detached Eddy Simulation for computing the steady and unsteady flow characteristics. The results show that the dual cavities arrangement accelerates complete combustion and modifies the flow structures due to intense shock shear layer interactions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Aerospace
Singeetham Pranaykumar, Dinesh Mengu, Akshay Prakash
Summary: An innovative air-throttling injection mechanism is proposed and investigated in this study, aiming to improve the combustion efficiency and mixing efficiency in scramjets. The mechanism shows promising results in terms of flame stabilization, combustion efficiency, and shorter ignition length even at higher Mach numbers.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
A. C. Rajesh, S. Jeyakumar, Kandasamy Jayaraman, Mehmet Karaca, A. Antony Athithan
Summary: The effect of dual cavity locations with strut injection configuration on supersonic flow under reacting conditions is evaluated numerically. The study investigates the shock wave patterns and their association with shear layer mixing features at different locations of the top wall cavity and bottom wall cavity. The flow pattern, static pressure and temperature distributions, and performance analysis of the dual cavity designs associated with the results of the DLR scramjet are analyzed.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Aerospace
Subhasis Chakravarthy, Pitambar Randive, Sukumar Pati
Summary: This study numerically investigated the effect of air throttling on the combustion performance of an ethylene-fueled scramjet combustor, showing that the flow rate and location of throttling have a strong interplay with combustion efficiency. The introduction of air throttling enhanced combustion efficiency due to the generation of pre-combustion shock train, with optimum efficiency achieved when throttling is about 20% of the inlet mass flow rate at a specific distance downstream from the cavity.
Article
Engineering, Aerospace
Suneetha Lakka, Pitambar Randive, K. M. Pandey
Summary: The study compares the combustion characteristics of combustors with and without cavities and investigates the impact of cavity parameters on the performance of a strut-based scramjet combustor. The research reveals the formation of a strong recirculation zone in the cavity region, improving mixing and combustion efficiency.
Article
Chemistry, Physical
Prasanth P. Nair, Vinod Narayanan, Abhilash Suryan
Summary: In a study on Scramjet engines, the placement of trailing struts plays a crucial role in enhancing combustion efficiency. Different strut configurations have varying effects on combustion performance, with configurations introducing high-pressure regions outperforming others. The addition of trailing struts leads to increased combustion efficiency and total pressure loss in the engine.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Mechanics
Prasanth P. Nair, Abhilash Suryan, Vinod Narayanan
Summary: Combustion at supersonic speeds is crucial for improving performance. The research discovers that the divergence angle of the passive strut has an impact on the mixing efficiency and acoustic behavior. Unstable combustion occurs when the divergence angle is too high, while pressure loss decreases with a smaller divergence angle.
Article
Engineering, Aerospace
Amit Thakur, Nishanth Thillai, Amritesh Sinha
Summary: Numerical simulations were conducted to study non-reacting and reacting flow behind a rearward step flameholder in Mach 1.6 supersonic flow with fuel injection at the step base. The findings indicated that injecting air in tandem with hydrogen at the step base showed the most improvement in combustion characteristics compared to other configurations.
PROPULSION AND POWER RESEARCH
(2021)
Article
Thermodynamics
A. Antony Athithan, S. Jeyakumar
Summary: This numerical study analyzes the performance of double ramps in a strut injection scramjet combustor. The results show that the dual ramps can decelerate the flow downstream of the combustor, creating recirculation regions that help in anchoring the flame. Additionally, the combustion efficiency increases as the ramps are positioned downstream of the strut injector.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2023)
Article
Chemistry, Physical
Sai Sreekar Yarasai, Dineshkumar Ravi, Sharan Yoganand, Thundil Karuppa Raj Rajagopal
Summary: A numerical investigation was conducted to analyze the performance and combustion characteristics of a scramjet combustor with and without a cavity. Different geometrical shapes of injectors were considered, including circle, square, and rectangle. The results showed that the circular injector with a cavity exhibited better mixing and combustion characteristics compared to the other injector models.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
A. Antony Athithan, S. Jeyakumar, Norbert Sczygiol, Mariusz Urbanski, A. Hariharasudan
Summary: This paper investigates the influence of ramps located upstream of a strut-based scramjet combustor under reacting flow conditions. The numerical results are validated with experimental values, showing compliance within the range, and the shock reflection due to the ramps enhances hydrogen distribution in the spatial direction, while lowering the combustion ignition delay time.
Article
Thermodynamics
Fuxu Quan, Juntao Chang, Chen Kong, Chengkun Lv, Guangwei Wu
Summary: This study investigates the fuel injection strategy and the effect of supplemental oxygen on the mixing performance in a scramjet combustor through large eddy simulations. The results show that injecting fuel from the upstream nozzle enhances mixing efficiency compared to the downstream nozzle. Additionally, supplementing oxygen at the trailing edge of the strut significantly improves turbulence and enhances fuel and oxidizer mixing.
APPLIED THERMAL ENGINEERING
(2024)
Article
Chemistry, Physical
S. K. Kireeti, Gadepalli Ravikiran Sastry, Santhosh Kumar Gugulothu
Summary: A detailed numerical analysis is conducted on a cavity-based scramjet combustor with an innovatively shaped strut and multi strut. The study reveals that the multi strut improves mixing and combustion efficiency compared to the single strut.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Obula Reddy Kummitha, K. M. Pandey, Anil Kumar Reddy Padidam
Summary: The research introduces an innovative fuel injection strut to enhance mixing performance by increasing interactions between shock wave and shear mixing layer. Numerical analysis shows that the new strut significantly improves mixing efficiency compared to the basic wedge design.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Engineering, Aerospace
Lakka Suneetha, Pitambar Randive, K. M. Pandey
Summary: The study reveals that self-throttling significantly affects the combustion performance of a strut-based scramjet combustor, improving mixing efficiency and enhancing fuel combustion. Additionally, the key factor influencing performance is the distance of self-throttling from the inlet.
Article
Thermodynamics
N. Satish, K. Venkatasubbaiah
JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS
(2019)
Article
Engineering, Aerospace
Veeresh Tekure, K. Venkatasubbaiah
AEROSPACE SCIENCE AND TECHNOLOGY
(2020)
Article
Thermodynamics
N. Satish, K. Venkatasubbaiah
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2020)
Editorial Material
Mechanics
N. Om Prakash Raj, K. Venkatasubbaiah
Article
Mechanics
Veeresh Tekure, K. Venkatasubbaiah
Summary: Numerical study of conjugate heat transfer in supersonic turbulent flow over a flat plate with finite thickness shows lower interface temperature and fluid temperature variation compared to non-conjugate heat transfer analysis. Results indicate significant increase in interface temperature for low thermal conductivity plate materials, and negligible effect of plate thickness on flow field temperature variation. Additionally, the maximum interface temperature increases with plate thickness.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2021)
Article
Thermodynamics
Abhijith Mullakkal Sasidharan, Kondapalli Venkatasubbaiah
Summary: An in-house Fortran-based solver is used to study numerically the forced convection flow of water-based and liquid metal gallium-based alumina-copper hybrid nanofluid through a wide rectangular mini channel in the laminar regime. The addition of copper nanoparticles improves the heat transfer performance of both liquid gallium and pure water, and the heat transfer performance of water-based hybrid nanofluids shows significant changes with variations in Reynolds number and particle concentration.
HEAT TRANSFER ENGINEERING
(2023)
Article
Mechanics
Veeresh Tekure, Pratik Shrikant Pophali, K. Venkatasubbaiah
Summary: The study found a significant reduction in total drag force with an increase in aerospike semi-cone angle at a fixed spike length to blunt-body diameter ratio. Lateral injection improved aerodynamic heat reduction capability, while a small bump on the spike stem proved to be more effective in reducing aerodynamic drag.
Article
Mechanics
Leelasagar Koneti, K. Venkatasubbaiah
Summary: A comprehensive comparison of fluid flow and heat transfer characteristics inside a square enclosure with water or liquid gallium as fluids under natural convection has been studied numerically. The study found significant differences in the flow and heat transfer characteristics between conventional fluids like water and low Prandtl number fluids like liquid gallium. The diffusion mechanism is dominant in liquid gallium while convection is dominant in water. The heat transfer in liquid gallium is 25.61 times greater than in water at a Grashof number of 103. A correlation for average Nusselt number is developed for liquid gallium fluid in the range of Grashof number from 10(3) to 10(6).
INTERNATIONAL JOURNAL OF FLUID MECHANICS RESEARCH
(2023)
Article
Thermodynamics
M. S. Abhijith, K. Venkatasubbaiah
Summary: In this study, an in-house Fortran-based two-phase Eulerian-Eulerian solver is used to investigate an impinging jet in a minichannel using microencapsulated phase change material (MEPCM)-water slurry. The heat transfer performance of water-based n-eicosane and n-octadecane MEPCM slurries are examined, and the melting pattern of the particles within the minichannel is reported at various parameters. The research quantifies the heat transfer enhancement of the MEPCM-water slurry and identifies the optimal conditions for a water-based n-eicosane slurry at Re = 100 and epsilon(s) = 1%.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Thermodynamics
Veeresh Tekure, K. Venkatasubbaiah
Summary: The numerical investigation of supersonic turbulent non-reacting flow through a cavity-type flameholder in scramjet engines reveals the significant impact of subcavity types, aspect ratios, and locations on recirculation patterns and strengths.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Thermodynamics
M. S. Abhijith, K. Venkatasubbaiah
Summary: The study shows that significant heat transfer enhancement is observed in MEPCM-water slurry compared to pure water as particles undergo melting. Furthermore, heat transfer enhancement increases with an increase in particle concentration. Using a combination of different phase change materials with varied melting temperatures can help maintain the melting of particles throughout the channel, leading to enhancement of heat transfer performance.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Thermodynamics
M. S. Abhijith, K. Venkatasubbaiah
Summary: In this study, laminar forced convection of copper oxide and titanium oxide water-based nanofluid flow through a microchannel was numerically investigated. The results showed significant heat transfer enhancement with increasing Reynolds number and nanoparticle volume concentrations.
COMPUTATIONAL THERMAL SCIENCES
(2021)
Article
Thermodynamics
M. S. Abhijith, K. Venkatasubbaiah
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2020)
Article
Nuclear Science & Technology
N. Satish, K. Venkatasubbaiah
JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE
(2020)
Article
Thermodynamics
N. Satish, K. Venkatasubbaiah
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2019)
