Article
Engineering, Aerospace
Yoonsik Park, Junhyuk Nam, Yongsu Kim, Daeyong Jun, Bok Jik Lee, Yang Ji Lee
Summary: Various flow control devices, especially bleed systems, have been developed to suppress inlet unstart and reduce total pressure loss in hypersonic inlets. Numerical simulations are crucial for investigating the effectiveness of different bleed configurations, but predicting the flow structure and bleed effects is challenging due to factors such as shock-wave/boundary-layer interactions and compressibility effects. A numerical solver was developed and evaluated on validation cases, showing accurate results in flat plate flows but requiring turbulence corrections for rapid expansion or curved walls in hypersonic inlets. This paper provides best practices for hypersonic flow cases and can guide future numerical studies on hypersonic inlet boundary layer control.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Aerospace
Zuwei Tan, Runze Li, Yufei Zhang
Summary: The inlet is a crucial component of hypersonic vehicles, and the design and optimization of the hypersonic inlet are of great importance. Artificial intelligence techniques, such as variational autoencoder (VAE) and generative adversarial network (GAN), have been used to improve aerodynamic optimization efficiency. This study applies a hybrid multilayer perceptron (MLP) combined with a VAE network to reconstruct and predict the flow field of a two-dimensional multiwedge hypersonic inlet. The results demonstrate that the VAE network accurately reconstructs the overall flow structure of the hypersonic flow field and achieves satisfactory reconstruction accuracy for complex flow structures.
Article
Engineering, Aerospace
Nurfathin Zahrolayali, Mohd Rashdan Saad, Azam Che Idris, Mohd Rosdzimin Abdul Rahman
Summary: This study computationally investigated the use of a heat source to regulate the shock wave-boundary layer interaction (SWBLI) of hypersonic inlets during throttling. The results showed that varying the size and power of the heat source influenced the shockwaves and affected the SWBLI within the inlet, resulting in changes in performance measures.
Article
Engineering, Aerospace
Zonghan Yu, Huihui Huang, Ruilin Wang, Yuedi Lei, Xueyang Yan, Zikang Jin, Omer Musa, Guoping Huang
Summary: This study compares the aerodynamic characteristics of two hypersonic inlets under non-uniform inflow conditions and finds that the side-spillage inlet has smaller dimensions and a stronger shock system, enabling better suppression of pressure fluctuations from the downstream combustion chamber, as well as a larger start margin.
Article
Engineering, Aerospace
Wei Yao, Hang Liu, Lianjie Xue, Yabing Xiao
Summary: The study found that a full-scale scramjet engine can achieve net thrust in the range of low dynamic pressure below 37 kPa and high range above 55 kPa, with combustion efficiencies varying from 66% to 82%. The rule of mixed is burnt was observed along with upstream propagation of combustion. However, unstart may occur in specific cases, such as Mach 7 at 30 km altitude.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Aerospace
You Wu, Jiwu Liu, Jian Peng, Xu Xu, Bing Chen, Qingchun Yang
Summary: This study investigates the effect of thermal nonequilibrium on the mass flow rate of a scramjet inlet using numerical simulations. The results show that there is a significant difference in mass flow rate between thermal nonequilibrium and equilibrium conditions due to the difference in oblique shock wave angles. Therefore, the effect of thermal nonequilibrium cannot be ignored for scramjet in some cases.
Article
Engineering, Aerospace
Shu-Zi Yang, Kai Liao, Wen-Zhong Xie, Yan-Jun Yue, Lin-Lin Yang, Shengmin Guo
Summary: In order to expand the stable operating range of hypersonic aircrafts, the mechanisms of hysteresis phenomenon in hypersonic inlets under acceleration/deceleration conditions were investigated. By conducting unsteady flowfield simulations on two typical 2D hypersonic inlets, two dominant characteristics of the hysteresis phenomenon during the acceleration/deceleration processes were identified. Two proposed mechanisms were used to explain the hysteresis phenomenon.
JOURNAL OF AEROSPACE ENGINEERING
(2023)
Article
Engineering, Aerospace
Manoj Kumar K. Devaraj, Prahallada Jutur, Srisha M. Rao, Gopalan Jagadeesh, Ganesh T. K. Anavardham
Summary: Understanding the mechanism of local unstart in a mixed compression scramjet intake is crucial for its stable off-design operation. Experimental and numerical studies were conducted to investigate the local unstart behavior of a hypersonic scramjet intake, revealing the significant impact of internal contraction ratio on local unstart and the driving role of shear layer in self-sustained oscillations during dynamic cowl experiments.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Aerospace
He-Xia Huang, Hui-Jun Tan, Jia Cai, Shu Sun
Summary: This paper experimentally studied the restart processes of two hypersonic inlets, finding that the internal contraction ratio affects the restart process. Evaluation of the inlet's starting capability must be examined carefully.
Article
Engineering, Aerospace
Wei-Yi Su, Hang An, Mou-Yuan Wang
Summary: Considering fluid-thermal-structural interaction (FTSI) is crucial in designing scramjet inlet for sustained hypersonic flight. A three-dimensional FTSI framework was developed and validated to understand the aerothermal and aeroelastic responses of planar hypersonic inlets under different flight Mach numbers and aspect ratios. The study reveals that FTSI improves contraction ratio, actual mass flow rate, and pressure ratio while decreasing total pressure ratio by up to 14.64%.
Article
Thermodynamics
M. Ram Prabhu, C. Balaji, T. Sundararajan, M. J. Chacko
Summary: In this study, both standard design correlations and numerical flow simulations were used to estimate the aerodynamic heating levels on a typical inlet configuration of a scramjet engine. The results were validated with in-house measurements and flight experiments, confirming the appropriateness of the design correlations. The numerical simulations also identified potential augmented heating zones, which are critical for long-duration scramjet missions.
JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS
(2022)
Article
Thermodynamics
N. K. Gopinath, K. V. Govindarajan, D. Roy Mahapatra
Summary: This paper presents a three-dimensional transient fluid-thermo-structural study of an actively cooled sandwich panel under hypersonic accelerating-cruise flight conditions. The study shows that an actively cooled system with fuel can effectively reduce bending deformation and improve thermal safeguard capacity compared to a passive approach. The use of fuel as a coolant has a significant influence on combustion efficiency and the associated complexity and trade-off in heat transfer and thermo-structural deformation behavior.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
N. K. Gopinath, K. V. Govindarajan, D. Roy Mahapatra
Summary: This paper presents a study on the three-dimensional transient fluid-thermo-structural behavior of an actively cooled sandwich panel under hypersonic accelerating-cruise flight conditions. The results show that active cooling can effectively control thermo-structural deformation and improve combustion efficiency.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mechanics
Chen Kong, Juntao Chang, Yunfei Li, Ziao Wang
Summary: Through a data-driven approach, a deep learning model based on CNN successfully learned the relationship between the velocity field and the wall pressure in the isolator, and accurately reconstructed the velocity field under different Mach numbers and backpressures.
Article
Engineering, Aerospace
Omer Musa, Guoping Huang, Zonghan Yu
Summary: This article introduces and evaluates a new pressure-corrected osculating axisymmetric flows design approach for the three-dimensional internal waverider intake. The results show that the pressure-corrected wavecatcher intakes exhibit improved performance compared to the uncorrected wavecatcher intakes.
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)
