Article
Engineering, Aerospace
Gautam Choubey, Malhar Solanki, Tathya Bhatt, G. Kshitij, D. Yuvarajan, Wei Huang
Summary: The major issue in improving the efficiency of the scramjet engine is ensuring adequate hydrogen fuel distribution within the supersonic chamber. The cavity floor injection strategy is a promising approach to keeping the flame stable under a wide range of operational conditions. The simulation results indicate that as the free-stream Mach number rises, the circulations inside the cavity become more intense, resulting in the formation of a stable igniting zone inside the cavity. The effect of different cavity floor length injection on the performance of the combustor has also been explored, with the optimum cavity floor length found to be 45 mm.
Article
Engineering, Aerospace
Hao-Yang Peng, Shi-Jie Liu, Wei-Dong Liu, Xue-Qiang Yuan, Xiao-Dong Cai
Summary: The study reveals that the length-to-depth ratio (L/D) of the cavity significantly affects the enhancement effects of continuous rotating detonation (CRD), proper cavity design can strengthen the CRD effect, achieving a mode transformation in propagation mode.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Aerospace
Xiang Li, Qingchun Lei, Xiaocun Zhao, Wei Fan, Shuang Chen, Li Chen, Ye Tian, Quan Zhou
Summary: The combustion characteristics of a hydrogen-fueled supersonic combustor with a large cavity length-to-depth ratio were investigated through experimental trials. The study found that the position of fuel injection and equivalence ratio play important roles in flame stabilization, which was demonstrated by POD and DMD analyses. The findings provide preliminary guidance for exploring the feasibility of using cavity combustors with large length-to-depth ratios in scramjet engines.
Article
Engineering, Aerospace
Guangwei Ma, Mingbo Sun, Fan Li, Yixin Yang, Yuhui Huang, Hongbo Wang
Summary: The study investigates the mixing and combustion characteristics of a model scramjet combustor with a rear-wall-expansion cavity under different parameters using experimental and numerical methods. Experimental results indicate that longer fuel injection distance and smaller cavity depth result in weaker flame and lower wall pressure, while shallower cavity leads to stronger flame oscillation. Shorter injection distance and larger cavity depth can suppress flame oscillation for robust combustion. Numerical simulation reveals that shorter injection distance promotes mixing efficiency by intensively interacting shear layer with fuel jets. The oscillation of cavity shear layer in smaller depth cavity enhances mixing efficiency but is detrimental to combustion. Proper cavity depth is crucial for cavity flameholder design.
Article
Mechanics
Shengzu Guo, Xu Zhang, Qili Liu, Lianjie Yue
Summary: The periodic flame flashback phenomenon was numerically studied in an ethylene-fueled scramjet combustor using a 3D unsteady Navier-Stokes solver. The study revealed that the combustion oscillations and flame flashbacks were maintained in the separated scramjet mode, not connected to the ramjet/scramjet mode transitions. A mechanism with four evolution stages was proposed to explain the flow-flame interaction.
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
Thermodynamics
Rong Feng, Jiajian Zhu, Zhenguo Wang, Mingbo Sun, Hongbo Wang, Zun Cai, Bin An, Liang Li
Summary: A gliding arc discharge was used to ignite an ethylene-fueled scramjet combustor with an inflow speed of Ma = 2.92. The ignition process can be classified into direct ignition mode and re-ignition mode, with re-ignition mode being more likely in a local fuel-lean environment, exhibiting longer flame propagation time and a smaller flame kernel.
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
Xu Zhang, Qifan Zhang, Zhenjie Wu, Lianjie Yue, Zhanbiao Gao, Weihang Luo, Hao Chen
Summary: Hysteresis and catastrophes were observed in a cavity-based scramjet combustor, breaking traditional knowledge about their relationship with ramjet/scramjet mode transitions. The first hysteresis and catastrophes were attributed to flame stabilization mode transitions, while the second were linked to flame/shock interaction mode transitions.
CHINESE JOURNAL OF AERONAUTICS
(2022)
Article
Energy & Fuels
Obula Reddy Kummitha, K. M. Pandey
Summary: The global demand for enhanced scramjet engine performance is increasing, with the main challenge being the mixing of fuel and air. Research has shown that using a wavy wall surface and double strut fuel injector can significantly improve mixing efficiency and combustion phenomenon.
Article
Chemistry, Physical
Long Gao, Xin Yu, Jiangbo Peng, Ye Tian, Zhen Cao, Fuyu Zhong, Guohua Wu, Minghong Han
Summary: This study investigates the combustion and oscillation behaviors in a hydrogen-fueled cavity-stabilized scramjet combustor using a high-speed PLIF technique. The spatial distribution of the flame structure under different fuel injection conditions is studied. The results reveal the shift in flame peak position downstream of the cavity with increasing injection pressure. The dynamic characteristics of flames under different flow conditions are analyzed, and the correlation between flame features and hydrogen injection conditions is obtained.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
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
Mingjiang Liu, Mingbo Sun, Guoyan Zhao, Yu Meng, Yuhui Huang, Guangwei Ma, Hongbo Wang
Summary: The relationship between thrust performance and combustion mode in a scramjet combustor was investigated through numerical simulations and experiments to verify the reliability of the numerical method. Different combustion modes were identified, and the impact of these modes on thrust performance and the possibility for performance improvement under different Mach numbers were discussed.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
Dongpeng Jia, Jun Yang, Chaoyang Liu, Long Jin, Dezhi Zhang, Min Zhang, Jin Li
Summary: An experimental study was conducted on the dynamic response characteristics of the flame in a cavity-based scramjet combustor during a sudden increase in global equivalence ratio during condition transition. Three flame modes were observed and analyzed using high-speed photography, showing that intense periodic flame flashback occurs when the injection pressure difference exceeds a critical value. The dominant frequency of flame flashback decreases and the contrast of combustion intensity becomes more obvious as the injection pressure difference increases.
Article
Energy & Fuels
Naresh Relangi, Antonella Ingenito, Suppandipillai Jeyakumar
Summary: This paper investigates the effect of cavity-based injection in an axisymmetric supersonic combustor using numerical simulation. The results show that transverse injection enhances combustion efficiency in the cavity region while also increasing total pressure loss.
Article
Thermodynamics
Pinku Debnath, K. M. Pandey
Summary: The study investigates the effect of modified ejector on detonation combustion wave propagation and propulsion thrust of liquid kerosene and gaseous hydrogen-air mixture. Simulation results show that the thrust force augmentation of hydrogen-air mixture is greater compared to liquid kerosene-air mixture, but the flame propagation velocity is faster for hydrogen-air combustion.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(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
Engineering, Multidisciplinary
Namrata Bordoloi, Krishna Murari Pandey, Kaushal Kumar Sharma
Summary: The study reveals that analyzing the supersonic combustor ramjet engine through a simulation model can effectively replicate experimental results. Different incoming Mach numbers result in varying combustion and mixing efficiencies. The maximum temperature rise is 2711.467 K, with maximum combustion and mixing efficiencies of 87.47% and 98.15% respectively.
MATHEMATICAL PROBLEMS IN ENGINEERING
(2021)
Article
Thermodynamics
Prince Kumar, Krishna Murari Pandey
Summary: A comprehensive numerical analysis was conducted to examine the transport characteristics of flow of Newtonian fluid inside a channel with a porous slab and internal wavy walls. It was found that heat transfer rate and pressure drop increase with rising Reynold number, Darcy number, and wavy wall's amplitude. Additionally, the enhancement ratio (ER) reaches its maximum value of 10.8 for Da = 10(-2) and Re = 1200.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2021)
Article
Engineering, Multidisciplinary
Akhileshwar Singh, Krishna Murari Pandey, Yogesh Singh
Summary: This study investigates the splitting dynamics of low-viscous fingers inside bifurcating channels through the manipulation of surface wettability. Numerical simulations reveal that the behavior of finger splitting depends on various parameters, including surface wettability, capillary number, viscosity ratio, and surface tension. The findings provide insights into biofluid mechanics and respiratory diseases such as COVID-19.
MATHEMATICAL PROBLEMS IN ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Durgesh Kumar Mishra, Sumit Bhowmik, Krishna Murari Pandey
Summary: This study discusses the thermal exploration of melting phenomena of beeswax-based phase change material of four different annulus shapes. Numerical investigation on composite-beeswax approach with metal oxide particles revealed improved melting rate and heat transfer. The type of metal oxide particles had minimal impact on melting rate and heat transfer, showing significant enhancements with their presence.
MATHEMATICAL PROBLEMS IN ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Dipak Debbarma, Krishna Murari Pandey, Abhishek Paul
Summary: This study investigates the enhancement of overall performance in heat sinks by using a double layer structure with protrusions and dimples. Comparisons between microsinks with protruded-dimpled bottom layer and microsinks with protruded-dimpled layers were made, with staggered arrangements showing superior overall performance. The heat sink with both layers protruded and dimpled was found to be optimal, offering excellent thermal performance.
MATHEMATICAL PROBLEMS IN ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Bandi Venkata Ramana Reddy, Saikat Ranjan Maity, Lokeswar Patnaik, Sunil Kumar, Krishna Murari Pandey
Summary: Al-6Si-18Pb alloy was fabricated using spray deposition method and warm rolling, and the microstructural change and mechanical properties were studied. The results showed that continuous and discontinuous dynamic recrystallisation occurred in the alloy after warm rolling, resulting in grain refinement. Furthermore, Pb atoms were homogeneously distributed in the Al matrix. The porosity and hardness of the samples were significantly affected after warm rolling.
ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES
(2022)
Article
Thermodynamics
Prince Kumar, Ritesh Dwivedi, K. M. Pandey
Summary: This study numerically investigates the impact of different Prandtl numbers on the thermo-hydraulic transport characteristics of a partial porous wavy channel for a laminar flow. The results show that increasing the Prandtl number and Reynolds number leads to an increase in the Nusselt number and enhancement ratio, while the performance factor deteriorates with increasing slab thickness. Additionally, the effect of different Darcy numbers was evaluated.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Thermodynamics
Prince Kumar, K. M. Pandey
Summary: This article investigates the effect of varying porous slab thicknesses and Darcy number on the thermohydraulic performance of corrugated channels. The results show that increasing the porous slab thickness and decreasing the Darcy number can enhance the thermal performance but reduce the hydraulic performance.
Article
Thermodynamics
Prince Kumar, Ritesh Dwivedi, Krishna Murari Pandey
Summary: Comprehensive numerical simulations are conducted to investigate the combined effect of three distinct passive techniques on thermo-hydraulic properties and entropy generation in three different wavy channels. It is found that the insertion of porous media between the corrugated walls enhances thermal performance, and the trapezoidal channel shows the highest enhancement by 90%.
HEAT TRANSFER ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Akhileshwar Singh, Deepak Kumar Singh, Yogesh Singh, Krishna Murari Pandey
Summary: This paper investigates the influence of viscosity ratio and surface wettability on immiscible viscous fingering instability within a rectangular channel. The findings reveal that higher viscosity ratios lead to increased displacement efficiency, while low viscosity ratios result in necking. The finger-shaped pattern splits into two parts at a wettability of 15 degrees, and no splitting occurs beyond this threshold. Furthermore, a transition from hydrophilic to superhydrophobic wettability abolishes necking and enhances displacement efficiency, with the instability shifting towards the left side.
INTERNATIONAL JOURNAL OF MODERN PHYSICS C
(2023)
Proceedings Paper
Materials Science, Multidisciplinary
Plabita Sonowal, K. M. Pandey, K. K. Sharma
Summary: Landing gear design is a crucial aspect in aircraft design, with shock absorbers being one of the key components that need to be carefully designed. This study focused on the structural analysis of a landing gear shock absorber model for the Boeing 787-8 in static conditions, with results showing that the high strength stainless steel model exhibited lower stress and deformation.
MATERIALS TODAY-PROCEEDINGS
(2021)
Proceedings Paper
Engineering, Mechanical
R. R. Kumar, K. M. Pandey, S. Dey
RELIABILITY, SAFETY AND HAZARD ASSESSMENT FOR RISK-BASED TECHNOLOGIES
(2020)
Article
Engineering, Aerospace
A. I. Krikunova, A. D. Cheshko, V. V. Krivets
Summary: Fire safety is crucial for the development of efficient and safe energy systems for space objects. This paper focuses on studying the influence of gravity on combustion processes and analyzes the dynamics of inverted conical methane-air flame under external acoustic excitation. The results show that at high excitation frequencies, the intensity of vortex generation is similar to that observed in experiments with normal gravity, indicating the dominance of acoustic mechanism. Additionally, at an external excitation frequency of 240 Hz, significant growth in shear vortex diameters and increased amplitude of perpendicular oscillations of flame branches were observed, indicating the most intensive large scale instability of flow.
Article
Engineering, Aerospace
Liya Huang, Mingquan Gong, Jiarui Zhang, Kun Liang, He Yang
Summary: Metallized gel propellants with exceptional stability and remarkable shear-thinning properties were successfully synthesized by utilizing cooperative hydrogen bonding between polymer octanoyl cellulose and the small Thixatrol ST molecule.
Article
Engineering, Aerospace
Clemence Poirier, Michelle Hermes, Marco Aliberti
Summary: This paper examines the role of space-based data in European climate policies and assesses the barriers to the use of space technology in climate policymaking in European countries. The research findings indicate that while satellite data is crucial for scientific research and climate policies, the role of space is not accurately reflected in European climate policies.
Article
Engineering, Aerospace
Yan-mei Zhou, Ji-ping Wu, Wei Huang, Gautam Choubey
Summary: This study investigates the combustion performance of sinusoidal pulsed jets in supersonic flows using numerical simulations. It is found that the pulsed jets can significantly improve combustion efficiency.
Article
Engineering, Aerospace
Wang Zhao, Shujun Tan, Yiliang Guo
Summary: This study proposes an adaptive Pogo active suppression controller design method that utilizes measured acceleration as feedback. The eigenspace transformation theory is employed to design dimensional reduced models for observer and adaptive controller, effectively addressing the issues of model parameter uncertainty and time-varying parameters. Simulation analysis of a certain type of rocket demonstrates the effectiveness of the proposed method.
Article
Engineering, Aerospace
A. V. Nebylov, V. A. Nebylov
Summary: This article discusses the safety issues of astronauts during the landing process and investigates how rescuers can effectively carry out rescue missions. The article also takes into account the special maritime conditions of the Vostochny cosmodrome.
Article
Engineering, Aerospace
Pietro Davide Maddio, Rosario Sinatra, Alberto Meschini, Riccardo Rigato, Marco Lapi, Davide Scarozza, Alessandro Cammarata
Summary: This study aims to develop a versatile cable net generation algorithm for designing offset cable nets in parabolic reflectors. The study proposes a methodology that leverages quasi-geodesic curves and introduces two types of these curves. The study also presents various solutions for different cable net layouts and introduces a quality index based on an equilateral triangle cable net.
Article
Engineering, Aerospace
Nahum Melamed, Tom Heinsheimer
Summary: Traditional methods of asteroid trajectory modification rely on impact or nuclear detonation, while centrifugal propulsion offers an alternative approach. The centrifuge system lands on the asteroid and gradually adjusts the trajectory using momentum transfer. This method allows for flexibility in operation parameters and has the potential to be used in planetary defense and other space missions.
Article
Engineering, Aerospace
Andrew Barth, Ou Ma
Summary: As humans continue to explore the surfaces of the Moon and Mars, the use of distributed heterogeneous robot teams can increase the chances of success by utilizing the complementary capabilities and synergy of the team members. Effective cooperation and collaboration between the members of a robot team is crucial, but defining a metric for effective cooperation is challenging. This paper presents a method for determining reward criteria that can be used for training robot swarm through reinforcement learning techniques. The trained robot team exhibits high success rates and cooperative behavior in test environments, demonstrating the robustness and scalability of the training strategies.
Article
Engineering, Aerospace
Kaijie Zhu, Qiquan Quan, Dewei Tang, Yachao Dong, Kaiyi Wang, Bo Tang, Qi Wu, Zongquan Deng
Summary: This study proposes a deployable Mars quadcopter for air patrol and sampling missions. By describing its structure, avionics architecture, and autonomous flight control method, it provides a feasible framework for future Mars flight sampling missions.
Article
Engineering, Aerospace
Avishai Melamed, Adi Rao, Sarah Kreps, Erika Palmer
Article
Engineering, Aerospace
Colin Hunter, Avinkrishnan Vijayachandran, Anthony M. Waas
Summary: Deployable structures inspired by origami have gained significant prominence in space applications. Recent advancements in multi-material additive manufacturing have opened new possibilities for the fabrication of monolithic structures. This paper presents a novel framework for designing deployable structures using viscoelastic hinges incorporated into rigid plates. Experimental results demonstrate the effectiveness and feasibility of these hinge designs in real-world applications.
Article
Engineering, Aerospace
Aleksander V. Efremov, Mikhail S. Tiaglik, Aleksey S. Tiaglik, Iliyas Kh Irgaleev, Tatyana V. Voronka
Summary: Theoretical and experimental studies were conducted to determine the best kind of information presented on a predictive display for the highest accuracy in space mission execution, while considering reduced propellant consumption.
Article
Engineering, Aerospace
Fuwen Liang, Long Miao, Feng Tian, Jiahui Song, Ningfei Wang, Xiao Hou
Summary: This study investigates the influence of deployment friction on the dynamic characteristics of nonconductive space tether through experimental measurement and numerical simulation. The results show that deployment friction significantly limits the uncontrolled tether deployment, while increasing the initial deployment velocity and satellite effective mass, as well as decreasing orbital altitude, can enhance the deployment capability and dynamic stability. In addition, an optimal matching relationship between tether length and satellite total mass is proposed, which is of substantial importance for the design of nonconductive space tether systems.
Article
Engineering, Aerospace
Amirah R. Algethami, Colin R. McInnes, Matteo Ceriotti
Summary: This paper utilizes the Hill's approximation model to manipulate the relative motion of two asteroids by three impulses, resulting in their bound binary motion in Earth's orbit. The feasibility of this strategy is demonstrated, and potential applications for parking small captured near-Earth asteroids in Earth's orbit are discussed.
