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Thomas Andreou; Craig White; Konstantinos Kontis; Shahrokh Shahpar; Nicholas Brown. Part 1: A Swirl Vane Generation Code for Fuel Spray Nozzles. 2021, 1 .
AMA StyleThomas Andreou, Craig White, Konstantinos Kontis, Shahrokh Shahpar, Nicholas Brown. Part 1: A Swirl Vane Generation Code for Fuel Spray Nozzles. . 2021; ():1.
Chicago/Turabian StyleThomas Andreou; Craig White; Konstantinos Kontis; Shahrokh Shahpar; Nicholas Brown. 2021. "Part 1: A Swirl Vane Generation Code for Fuel Spray Nozzles." , no. : 1.
Thomas Andreou; Craig White; Konstantinos Kontis; Shahrokh Shahpar; Nicholas Brown. Part 2: Design Optimisation Strategies for a Fuel Spray Nozzle. 2021, 1 .
AMA StyleThomas Andreou, Craig White, Konstantinos Kontis, Shahrokh Shahpar, Nicholas Brown. Part 2: Design Optimisation Strategies for a Fuel Spray Nozzle. . 2021; ():1.
Chicago/Turabian StyleThomas Andreou; Craig White; Konstantinos Kontis; Shahrokh Shahpar; Nicholas Brown. 2021. "Part 2: Design Optimisation Strategies for a Fuel Spray Nozzle." , no. : 1.
When compressed gas is ejected from a nozzle into a low-pressure environment, the shock wave diffracts around the nozzle lip and a vortex loop will form. The phenomenon has been widely investigated in the continuum flow regime, but how the shock diffraction and vortex behave under rarefied flow conditions has not received as much attention. It is necessary to understand this transient flow in rarefied environments to improve thrust vector control and avoid potential contamination and erosion of spacecraft surfaces. This work provides numerical results of the vortex loop formation caused by shock wave diffraction around a 90° corner using the direct simulation Monte Carlo method and the compressible Navier–Stokes equations with the appropriate Maxwell velocity slip and the von Smoluchowski temperature jump boundary conditions. The Mach number and rarefaction effects on the formation and evolution of the vortex loop are discussed. A study of the transient structures of vortex loops has been performed using the rorticity concept. A relationship of mutual transformation between the rorticity and shear vectors has been discovered, demonstrating that the application of this concept is useful to understand vortex flow phenomena.
Ziqu Cao; Craig White; Konstantinos Kontis. Numerical investigation of rarefied vortex loop formation due to shock wave diffraction with the use of rorticity. Physics of Fluids 2021, 33, 067112 .
AMA StyleZiqu Cao, Craig White, Konstantinos Kontis. Numerical investigation of rarefied vortex loop formation due to shock wave diffraction with the use of rorticity. Physics of Fluids. 2021; 33 (6):067112.
Chicago/Turabian StyleZiqu Cao; Craig White; Konstantinos Kontis. 2021. "Numerical investigation of rarefied vortex loop formation due to shock wave diffraction with the use of rorticity." Physics of Fluids 33, no. 6: 067112.
An experimental investigation of sonic transverse jets in Mach 5 cross flow over a flat plate with a sharp leading edge was carried out. Jet to free stream momentum flux ratio, J, was varied from 1.16 to 5.30. Schlieren visualisation provided information regarding mean flow features such as Mach disc height, h, separation length, xsep as well as inherent unsteadiness. Steady wall pressure measurements diagnosed the interaction region between the jet and the incoming cross flow developing on the flat plate. To assess the jet penetration characteristics and trajectories, two-component Particle Image Velocimetry (PIV) measurements were carried out at the centreplane of the flat plate. Raw PIV image analysis was used to specify jet penetration boundaries. Ensemble-averaged streamwise and transverse velocity contours revealed the mean flow structures. The barrel shocks and the Mach disc forming the jet boundary can be easily seen and were visualised/quantified using PIV measurement technique. Maximum turbulence occurred above the Mach disc due to the presence of the shear layer and at the intersection of the windward side of the barrel shock and bow shock.
Erinc Erdem; Konstantinos Kontis. Experimental investigation of sonic transverse jets in Mach 5 crossflow. Aerospace Science and Technology 2020, 110, 106419 .
AMA StyleErinc Erdem, Konstantinos Kontis. Experimental investigation of sonic transverse jets in Mach 5 crossflow. Aerospace Science and Technology. 2020; 110 ():106419.
Chicago/Turabian StyleErinc Erdem; Konstantinos Kontis. 2020. "Experimental investigation of sonic transverse jets in Mach 5 crossflow." Aerospace Science and Technology 110, no. : 106419.
A thermal fluctuation driven by a burst plasma discharge is experimentally investigated using a frequency analysis based on the Schlieren images. The burst plasma discharge is controlled by an interval frequency fint = 200 Hz and a pulse frequency fB = 3.6 kHz as well as the duration time of the burst event: Ton. A burst feature is defined as a burst ratio BR = Ton/(1/fint). The burst plasma discharge generates a burst-induced hot plume growing above a ground electrode. In a high burst ratio, which is BR = 0.45 and 0.57, the burst-induced hot plume is formed as a wave thermal pattern that is mainly fluctuated at the interval frequency of 200 Hz. Additionally, a maximum fluctuation spot of 200 Hz appears near the edge of an exposed electrode in a low burst ratio, whereas it moves towards the ground electrode in the high burst ratio. The possible scenario is that a relatively strong ionic wind and/or an induced jet generated in the high burst ratio might cause the movement of the maximum fluctuation spot.
Takahiro Ukai; Konstantinos Kontis. Thermal Fluctuation Characteristics around a Nanosecond Pulsed Dielectric Barrier Discharge Plasma Actuator using a Frequency Analysis based on Schlieren Images. Energies 2020, 13, 628 .
AMA StyleTakahiro Ukai, Konstantinos Kontis. Thermal Fluctuation Characteristics around a Nanosecond Pulsed Dielectric Barrier Discharge Plasma Actuator using a Frequency Analysis based on Schlieren Images. Energies. 2020; 13 (3):628.
Chicago/Turabian StyleTakahiro Ukai; Konstantinos Kontis. 2020. "Thermal Fluctuation Characteristics around a Nanosecond Pulsed Dielectric Barrier Discharge Plasma Actuator using a Frequency Analysis based on Schlieren Images." Energies 13, no. 3: 628.
Plasma actuators have attracted interest for use as active flow control devices due to their many benefits; they have no moving parts and are lightweight, can be flush mounted, and require low power. In this study, the performance of plasma actuators are experimentally characterized with dielectric material, dielectric thickness, and operating frequency for surface and channel actuator geometries. The channel height, changing the effective dielectric constant, is also varied. Induced velocities were measured using a pitot tube and PIV, and power consumption levels were recorded. For the surface plasma actuator, PTFE and GRE dielectric materials show similar performance, with Kapton producing the highest induced velocity jet. Higher plasma ionization tends to occur with operating frequencies of 5 and 10 kHz, with a minimum at 7 kHz – possibly related to a change to streamer discharge from corona discharge. Power consumption was also higher at frequencies of 5 and 10 kHz. Thinner dielectric materials outperformed thicker ones for a given high voltage input. GRE, which has the highest dielectric constant of the tested materials, resulted in higher induced velocities than PTFE and Kapton for the same dielectric thickness. For the channel actuator, the smallest air gap corresponding to the lowest permittivity generated the highest peak induced velocity at 12 kHz. Different air gap heights do not seem to affect the induced velocities for frequencies above 14 kHz. A high gradient of velocity reduction with streamwise distance from the exposed electrode of the channel actuators was also observed.
Michael M. Wojewodka; Craig White; Konstantinos Kontis. Effect of permittivity and frequency on induced velocity in ac-DBD surface and channel plasma actuators. Sensors and Actuators A: Physical 2020, 303, 111831 .
AMA StyleMichael M. Wojewodka, Craig White, Konstantinos Kontis. Effect of permittivity and frequency on induced velocity in ac-DBD surface and channel plasma actuators. Sensors and Actuators A: Physical. 2020; 303 ():111831.
Chicago/Turabian StyleMichael M. Wojewodka; Craig White; Konstantinos Kontis. 2020. "Effect of permittivity and frequency on induced velocity in ac-DBD surface and channel plasma actuators." Sensors and Actuators A: Physical 303, no. : 111831.
Dielectric barrier discharge (DBD) plasma actuators have received considerable attention by many researchers for various flow control applications. Having no moving parts, being light-weight, easily manufacturable, and their ability to respond almost instantly are amongst the advantages which has made them a popular flow control device especially for application on aircraft wings. The new configuration of DBDs which uses multiple encapsulated electrodes (MEE) has been shown to produce a superior and more desirable performance over the standard actuator design. The objective of the current study is to examine the effect of this new actuator configuration on the aerodynamic performance of an aerofoil under leading edge separation and wake interaction conditions. The plasma actuator is placed at the leading edge of a symmetric NACA 0015 aerofoil which corresponds to the location of the leading edge slat. The aerofoil is operated in a chord Reynolds number of \(0.2\,\times \,10^6\). Surface pressure measurements along with the mean velocity profile of the wake using pitot measurements are used to determine the lift and drag coefficients, respectively. Particle image velocimetry (PIV) is also utilised to visualise and quantify the induced flow field. The results show improvement in aerodynamic performances of aerofoil under leading edge separation and also facing the wake region.
Rasool Erfani; Kostas Kontis. MEE-DBD Plasma Actuator Effect on Aerodynamics of a NACA0015 Aerofoil: Separation and 3D Wake. Computational Methods in Applied Sciences 2019, 75 -92.
AMA StyleRasool Erfani, Kostas Kontis. MEE-DBD Plasma Actuator Effect on Aerodynamics of a NACA0015 Aerofoil: Separation and 3D Wake. Computational Methods in Applied Sciences. 2019; ():75-92.
Chicago/Turabian StyleRasool Erfani; Kostas Kontis. 2019. "MEE-DBD Plasma Actuator Effect on Aerodynamics of a NACA0015 Aerofoil: Separation and 3D Wake." Computational Methods in Applied Sciences , no. : 75-92.
Experimental investigations and numerical simulations of normal shock waves of different strengths propagating inside ducts with roughness are presented. The roughness is added in the form of grooves. Straight and branching ducts are considered in order to better explore the mechanisms causing attenuation of the shock and the physics behind the evolution of the complex wave patterns resulting from diffraction and reflection of the primary moving shock. A well-established finite-volume numerical method is used and further validated for several test cases relevant to this study. The computed results are compared with experimental measurements in ducts with grooves. Good agreement between high-resolution simulations and the experiment is obtained for the shock speeds and complex wave patterns created by the grooves. High-frequency response time histories of pressure at various locations were recorded in the experiments. The recorded pressure histories and shock strengths were found in fair agreement with the two-dimensional simulation results as long as the shock stays in the duct. Overall, the physics of the interactions of the moving shock and the diffracted and reflected waves with the grooves are adequately captured in the high-resolution simulations. Therefore, shocks propagating in ducts with different groove geometries have been simulated in order to identify the groove shape that diminishes shock strength.
S. M. Mortazawy; K. Kontis; J. Ekaterinaris. Normal shock wave attenuation during propagation in ducts with grooves. Shock Waves 2019, 30, 91 -113.
AMA StyleS. M. Mortazawy, K. Kontis, J. Ekaterinaris. Normal shock wave attenuation during propagation in ducts with grooves. Shock Waves. 2019; 30 (1):91-113.
Chicago/Turabian StyleS. M. Mortazawy; K. Kontis; J. Ekaterinaris. 2019. "Normal shock wave attenuation during propagation in ducts with grooves." Shock Waves 30, no. 1: 91-113.
This Special Issue contains selected papers from works presented at the 8th EASN–CEAS (European Aeronautics Science Network–Council of European Aerospace Societies) Workshop on Manufacturing for Growth and Innovation, which was held in Glasgow, UK, 4–7 September 2018
Spiros Pantelakis; Konstantinos Kontis. Special Issue “8th EASN–CEAS Workshop on Manufacturing for Growth and Innovation”. Aerospace 2019, 6, 84 .
AMA StyleSpiros Pantelakis, Konstantinos Kontis. Special Issue “8th EASN–CEAS Workshop on Manufacturing for Growth and Innovation”. Aerospace. 2019; 6 (8):84.
Chicago/Turabian StyleSpiros Pantelakis; Konstantinos Kontis. 2019. "Special Issue “8th EASN–CEAS Workshop on Manufacturing for Growth and Innovation”." Aerospace 6, no. 8: 84.
Michael M Wojewodka; Craig White; Takahiro Ukai; Andrew Russell; Konstantinos Kontis. Pressure dependency on a nanosecond pulsed dielectric barrier discharge plasma actuator. Physics of Plasmas 2019, 26, 063512 .
AMA StyleMichael M Wojewodka, Craig White, Takahiro Ukai, Andrew Russell, Konstantinos Kontis. Pressure dependency on a nanosecond pulsed dielectric barrier discharge plasma actuator. Physics of Plasmas. 2019; 26 (6):063512.
Chicago/Turabian StyleMichael M Wojewodka; Craig White; Takahiro Ukai; Andrew Russell; Konstantinos Kontis. 2019. "Pressure dependency on a nanosecond pulsed dielectric barrier discharge plasma actuator." Physics of Plasmas 26, no. 6: 063512.
The wake flow characteristics of a 1:20 scale articulated lorry model with a linear Alternate Current Dielectric Barrier Discharge (AC-DBD) plasma actuation implemented was experimentally investigated. Time-averaged velocity, turbulence, and vorticity information along the centreline of the model were constructed using a two-component particle image velocimetry technique. In addition, force balance was used to measure the time-average drag force acting on the model with and without the use of AC-DBD plasma actuation. In general, the AC-DBD plasma actuation showed negligible effect in changing the drag coefficient of the test model. Moreover, implementing the AC-DBD plasma actuation around the rear end of the trailer model could neither alter the size nor the reverse flow velocity in the wake region. In contrast, the AC-DBD plasma actuation increased the levels of fluctuation in the flow turbulence kinetic energy and vorticity but showed no observable effect to alter the frequency response of the flow in the wake region. It is deduced that the use of AC-DBD plasma actuation indeed generated no flow control effect at the rear end of an articulated lorry trailer.
Kin-Hing Lo; Rengarajan Sriram; Konstantinos Kontis. Wake Flow Characteristics over an Articulated Lorry Model with/without AC-DBD Plasma Actuation. Applied Sciences 2019, 9, 2426 .
AMA StyleKin-Hing Lo, Rengarajan Sriram, Konstantinos Kontis. Wake Flow Characteristics over an Articulated Lorry Model with/without AC-DBD Plasma Actuation. Applied Sciences. 2019; 9 (12):2426.
Chicago/Turabian StyleKin-Hing Lo; Rengarajan Sriram; Konstantinos Kontis. 2019. "Wake Flow Characteristics over an Articulated Lorry Model with/without AC-DBD Plasma Actuation." Applied Sciences 9, no. 12: 2426.
The flow field in a hypersonic inlet model at a design point of M = 6 has been studied experimentally. The focus of the current study is to present the time-resolved flow characteristics of separation shock around the cowl and the correlation between the separation shock oscillation induced by the unstart flow and the wall pressure fluctuation when the inlet is in a state of unstart. High-speed Schlieren flow visualization is used to capture the transient shock structure. High-frequency pressure transducers are installed on the wall around both the cowl and isolator areas to detect the dynamic pressure distribution. A schlieren image quantization method based on gray level detection and calculation is developed to analyze the time-resolved spatial structure of separation shock. Results indicate that the induced separation shock oscillation and the wall pressure fluctuation are closely connected, and they show the same frequency variation characteristics. The unsteady flow pattern of the “little buzz” and “big buzz” modes are clarified based on time-resolved Schlieren images of separation shock. Furthermore, the appropriate location of the pressure transducers is determined on the basis of the combined analysis of fluctuating wall-pressure and oscillating separation shock data.
Chengpeng Wang; Xin Yang; Longsheng Xue; Konstantinos Kontis; Yun Jiao. Correlation Analysis of Separation Shock Oscillation and Wall Pressure Fluctuation in Unstarted Hypersonic Inlet Flow. Aerospace 2019, 6, 8 .
AMA StyleChengpeng Wang, Xin Yang, Longsheng Xue, Konstantinos Kontis, Yun Jiao. Correlation Analysis of Separation Shock Oscillation and Wall Pressure Fluctuation in Unstarted Hypersonic Inlet Flow. Aerospace. 2019; 6 (1):8.
Chicago/Turabian StyleChengpeng Wang; Xin Yang; Longsheng Xue; Konstantinos Kontis; Yun Jiao. 2019. "Correlation Analysis of Separation Shock Oscillation and Wall Pressure Fluctuation in Unstarted Hypersonic Inlet Flow." Aerospace 6, no. 1: 8.
The thermal perturbation caused by a nanosecond pulsed dielectric barrier discharge (ns-DBD) plasma actuator may lead to boundary layer transition. Hence, understanding of the thermal flow induced by the ns-DBD plasma actuator will contribute to the development of an efficient flow control device for various engineering applications. In this study, the spatial density distribution related to the thermal flow was experimentally investigated using both qualitative and quantitative schlieren techniques. The focus of this study is to understand the initial temporal variation of the spatial density distribution above the ns-DBD plasma actuator in quiescent air. The quantitative visualisation showed that a hot plume is generated from the edge of the exposed electrode and moves slightly towards the ground electrode. A possible explanation is that an ionic wind and/or an induced jet leads to the movement of the hot plume. However, the plasma-induced flow (the ionic wind and the induced jet) is generated after the...
Takahiro Ukai; Andrew Russell; Hossein Zare-Behtash; Konstantinos Kontis. Temporal variation of the spatial density distribution above a nanosecond pulsed dielectric barrier discharge plasma actuator in quiescent air. Physics of Fluids 2018, 30, 116106 .
AMA StyleTakahiro Ukai, Andrew Russell, Hossein Zare-Behtash, Konstantinos Kontis. Temporal variation of the spatial density distribution above a nanosecond pulsed dielectric barrier discharge plasma actuator in quiescent air. Physics of Fluids. 2018; 30 (11):116106.
Chicago/Turabian StyleTakahiro Ukai; Andrew Russell; Hossein Zare-Behtash; Konstantinos Kontis. 2018. "Temporal variation of the spatial density distribution above a nanosecond pulsed dielectric barrier discharge plasma actuator in quiescent air." Physics of Fluids 30, no. 11: 116106.
This paper is a review of significant studies in the complex flow physics in diffusive, s-shaped ducts, focusing on flow control methods employed to counteract the onset of separation, swirl formation, and non-uniformity of pressure at the duct exit plane. Passive, active, and hybrid flow control, along with optimisation techniques used to control the dominant flow features are discussed. According to the literature, tapered fin vortex generators and submerged vortex generators improve pressure loss and distortion by double digit percentages, and three-dimensional synthetic jets and pulsed micro-jets show greatest promise amongst active flow control devices. Plasma flow control methods have only sparsely been used in s-ducts with one study performing experiments with alternating-current dielectric-barrier-discharge plasma actuators. The importance of flow unsteadiness has been identified in the literature, with peak values as high as one order of magnitude different from the time-averaged properties. Despite this, very few flow control studies have used time-dependent solution methods to quantify the effect of flow control methods on the unsteadiness of the flow.
Michael M Wojewodka; Craig White; Shahrokh Shahpar; Konstantinos Kontis. A review of flow control techniques and optimisation in s-shaped ducts. International Journal of Heat and Fluid Flow 2018, 74, 223 -235.
AMA StyleMichael M Wojewodka, Craig White, Shahrokh Shahpar, Konstantinos Kontis. A review of flow control techniques and optimisation in s-shaped ducts. International Journal of Heat and Fluid Flow. 2018; 74 ():223-235.
Chicago/Turabian StyleMichael M Wojewodka; Craig White; Shahrokh Shahpar; Konstantinos Kontis. 2018. "A review of flow control techniques and optimisation in s-shaped ducts." International Journal of Heat and Fluid Flow 74, no. : 223-235.
This paper presents the conceptual design and performance analysis of a partially reusable space launch vehicle for small payloads. The system employs a multi-stage vehicle powered by rocket engines, with a reusable first stage capable of glided or powered flight, and expendable upper stage(s) to inject 500 kg of payload into low Earth orbits. The space access vehicle is designed to be air-launched from a modified aircraft carrier. The aim of the system design is to develop a commercially viable launch system for near-term operation, thus emphasis is placed on the efficient use of high TRL technologies and on the commercial potential of the technical design. The vehicle design is analysed using a multi-disciplinary design optimisation approach to evaluate the performance, operational capabilities and design trade-offs. Results from two trade-off studies are shown, evaluating the choice wing area and thus aerodynamic characteristics, and the choice of stage masses and engines selection on the mission performance.
Christie Alisa Maddock; Lorenzo Ricciardi; Michael West; Joanne West; Konstantinos Kontis; Sriram Rengarajan; David Evans; Andy Milne; Stuart McIntyre. Conceptual design analysis for a two-stage-to-orbit semi-reusable launch system for small satellites. Acta Astronautica 2018, 152, 782 -792.
AMA StyleChristie Alisa Maddock, Lorenzo Ricciardi, Michael West, Joanne West, Konstantinos Kontis, Sriram Rengarajan, David Evans, Andy Milne, Stuart McIntyre. Conceptual design analysis for a two-stage-to-orbit semi-reusable launch system for small satellites. Acta Astronautica. 2018; 152 ():782-792.
Chicago/Turabian StyleChristie Alisa Maddock; Lorenzo Ricciardi; Michael West; Joanne West; Konstantinos Kontis; Sriram Rengarajan; David Evans; Andy Milne; Stuart McIntyre. 2018. "Conceptual design analysis for a two-stage-to-orbit semi-reusable launch system for small satellites." Acta Astronautica 152, no. : 782-792.
Takahiro Ukai; Konstantinos Kontis; Leichao Yang. Flow structure generated by laser-induced blast wave propagation through the boundary layer of a flat plate. Aerospace Science and Technology 2018, 78, 569 -573.
AMA StyleTakahiro Ukai, Konstantinos Kontis, Leichao Yang. Flow structure generated by laser-induced blast wave propagation through the boundary layer of a flat plate. Aerospace Science and Technology. 2018; 78 ():569-573.
Chicago/Turabian StyleTakahiro Ukai; Konstantinos Kontis; Leichao Yang. 2018. "Flow structure generated by laser-induced blast wave propagation through the boundary layer of a flat plate." Aerospace Science and Technology 78, no. : 569-573.
Background-oriented Schlieren (BOS) technique is a recently invented non-intrusive flow diagnostic method which has yet to be fully explored in its capabilities. In this paper, BOS technique has been applied for investigating the general flow field characteristics inside a generic scramjet inlet-isolator with Mach 5 flow. The difficulty in finding the delicate balance between measurement sensitivity and measurement area image focusing has been demonstrated. The differences between direct cross-correlation (DCC) and Fast Fourier Transform (FFT) raw data processing algorithm have also been demonstrated. As an exploratory study of BOS capability, this paper found that BOS is simple yet robust enough to be used to visualize complex flow in a scramjet inlet in hypersonic flow. However, in this case its quantitative data can be strongly affected by 3-dimensionality thus obscuring the density value with significant errors.
Azam Che Idris; Mohd Rashdan Saad; Kin Hing Lo; Konstantinos Kontis. Background-Oriented Schlieren (BOS) for Scramjet Inlet-isolator Investigation. IOP Conference Series: Materials Science and Engineering 2018, 370, 012003 .
AMA StyleAzam Che Idris, Mohd Rashdan Saad, Kin Hing Lo, Konstantinos Kontis. Background-Oriented Schlieren (BOS) for Scramjet Inlet-isolator Investigation. IOP Conference Series: Materials Science and Engineering. 2018; 370 (1):012003.
Chicago/Turabian StyleAzam Che Idris; Mohd Rashdan Saad; Kin Hing Lo; Konstantinos Kontis. 2018. "Background-Oriented Schlieren (BOS) for Scramjet Inlet-isolator Investigation." IOP Conference Series: Materials Science and Engineering 370, no. 1: 012003.
Two-dimensional direct simulation Monte Carlo simulations of the Edney Type IV shock interaction problem, where an oblique shock wave generated by a wedge encounters the bow shock from a cylinder, are carried out for three different Knudsen numbers using the dsmcFoam+ code. The numerical results for surface and flow properties are in good agreement with experiment for a Knudsen number of 0.0067. When the degree of rarefaction is increased, the oblique and normal shock waves become more diffuse and the bow shock standoff distance increases. The supersonic jet that forms in the interaction region becomes weaker as the Knudsen number increases and the point at where it impinges on the cylinder surface moves in a clockwise direction due to the jet being turned upward. The location of the peak heat transfer coefficient, peak pressure coefficient, and zero skin friction coefficient on the cylinder surface follow the supersonic jet impingement in a clockwise direction around the cylinder. The peak heat transfer and pressure coefficients decrease with increasing Knudsen number.
Craig White; Konstantinos Kontis. The Effect of Increasing Rarefaction on the Edney Type IV Shock Interaction Problem. Shock Wave Interactions 2018, 299 -311.
AMA StyleCraig White, Konstantinos Kontis. The Effect of Increasing Rarefaction on the Edney Type IV Shock Interaction Problem. Shock Wave Interactions. 2018; ():299-311.
Chicago/Turabian StyleCraig White; Konstantinos Kontis. 2018. "The Effect of Increasing Rarefaction on the Edney Type IV Shock Interaction Problem." Shock Wave Interactions , no. : 299-311.
Colour schlieren experimental results for Mach 5 flow over an arbitrary geometry that generates complex shock structures and shock interactions are presented. The experiment is rebuilt using the rhoCentralFoam solver to solve the compressible Navier–Stokes equations and a numerical analogue, the density gradients (i.e. pseudo-schlieren), is compared to the experimental result, showing very good qualitative agreement. The numerical results give data that can be post-processed to visualise the shock waves by taking advantage of changes in pressure, entropy, velocity, etc. across a shock, in addition to the gradients of density. It is shown that, at least for the geometry and Mach number studied here, the divergence of the velocity field produces the best numerical shock detection method.
Craig White; Konstantinos Kontis. Experimental and Numerical Visualisation of Supersonic Flow over the British Isles. Shock Wave Interactions 2018, 155 -164.
AMA StyleCraig White, Konstantinos Kontis. Experimental and Numerical Visualisation of Supersonic Flow over the British Isles. Shock Wave Interactions. 2018; ():155-164.
Chicago/Turabian StyleCraig White; Konstantinos Kontis. 2018. "Experimental and Numerical Visualisation of Supersonic Flow over the British Isles." Shock Wave Interactions , no. : 155-164.
Shock wave attenuation has been studied by using rough walls. The roughness at the walls is added by placing grooves. The experimental study employed a shock tube and non-electrical (NONEL) tube placed above the surface. The shock tube experiments were performed for driver gas (air) pressures of 4, 8 and 12 bar and atmospheric pressure within the driven section, giving theoretical Mach number of 1.34, 1.54 and 1.66, respectively. In the NONEL tube experiments, detonation initiates inside the NONEL tube, due to the reactants deposited on its internal surface, producing a blast wave and consequent products of combustion. High-speed schlieren photography and pressure measurements were employed to visualize and quantify the flow field.
K. Kontis. Shock Interactions with Structures and Their Associated Induced Flows. Understanding Built Environment 2017, 157 -170.
AMA StyleK. Kontis. Shock Interactions with Structures and Their Associated Induced Flows. Understanding Built Environment. 2017; ():157-170.
Chicago/Turabian StyleK. Kontis. 2017. "Shock Interactions with Structures and Their Associated Induced Flows." Understanding Built Environment , no. : 157-170.