Recent Submissions

  • Numerical study of oblique detonation wave control for fuel blends 

    Kore, Rushikesh; Vashishtha, Ashish (2023)
    The current study is motivated to develop control strategies for oblique detonation wave formation on a finite length wedge in a premixed methane-air mixture. The effectiveness of hydrogen blends (0 - 100%) to methaneair ...
  • Unsteady DSMC Simulation of blunt nose with spike at hypersonic rarefield flows 

    Ravuri, Nishita; Scully, Stephen; Vashishtha, Ashish (2023-03-29)
    To design an efficient ram-air intake for an air-breathing propulsion system for VLEO (Very-Low) / SLEO (Super Low) Earth Orbit satellites requires consideration of the unsteady effects in the hypersonic low-density or ...
  • Mach number dependence of flow instability around a spiked body 

    Vashishtha, Ashish; Khurana, Shashank (AIP Publishing, 2023-05-05)
    A forward-facing aerospike have been identified as a passive flow control device for enhancing the aerodynamic efficiency and reducing the heat transfer in high-speed flows. In addition, it has been reported that the ...
  • An assessment of radiation models utilized in CFD for thermal and fluid analysis in interior building spaces with large glazing 

    Samuel, Yona Arike; Confrey, Thomas; Vashishtha, Ashish; Callaghan, Dean; Nolan, Cathal (AIP Publishing, 2023)
    This paper investigates the effects of using the S2S and the DO method in the CFD simulation of a cavity to identify a convenient model for simulating radiative heat transfer. A 3D model for an office room fitted with a ...
  • A concept of aerospike nozzle for cold spray additive manufacturing: towards a potential solution for preventing the issue of clogging 

    Raoelison, Rija Nirina; Msolli, Sabeur; Deng, Sihao; Vashishtha, Ashish; Callaghan, Dean; Zaim-Mounajed, Wassim; Zhang, Teng; Padayodi, Essolé; Sagot, Jean-Claude; Raghavendra, Ramesh (ASM International, 2023-05-22)
    The clogging, a frequent gas passage deformation phenomenon because of powder accumulation on inner nozzle wall, is a major issue in long duration Cold Spray (CS) operations and a major challenge for Cold spray technology ...
  • Investigation of a modified circular nozzle for cold spray applications 

    Sharma, Amit Kumar; Vashishtha, Ashish; Callaghan, Dean; Bakshi, Srinivasan Rao; Kamaraj, M.; Raghavendra, Ramesh (ASM International, 2023-05-22)
    The current work numerically evaluates the efficacy of a coflowing nozzle for cold spray applications with the aim to mitigate nozzle clogging by reducing the length of its divergent section. The high-pressure nitrogen ...
  • QUBIC : exploring the primordial universe with the q&u bolometric interferometer 

    Mennella, Aniello; Ade, Peter; Amico, Giorgio; Auguste, Didier; Aumont, Jonathan; Banfi, Stephano; Barbarán, Gustavo; Battaglia, Paola; Battistelli, Elia; Bau, Alessandro; Bélier, Benoit; Bennett, David G.; Bergé, Laurent; Bernard, Jean Philippe; Bersanelli, Marco; Bigot Sazy, Marie Anne; Bleurvacq, Nathan; Bonaparte, Juan; Bonis, Julien; Bunn, Emory; Burke, David; Buzi, Daniele; Buzzelli, Alessandro; Cavaliere, Francesco; Chanial, Pierre; Chapron, Claude; Charlassier, Romain; Columbro, Fabio; Coppi, Gabriele; Coppolecchia, Alessandro; D'Agostino, Rocco; D'Alessandro, Giuseppe; De Bernardis, Paolo; De Gasperis, Giancarlo; De Leo, Michele; De Petris, Marco; Di Donato, Andres; Dumoulin, Louis; Etchegoyen, Alberto; Fasciszewski, Adrián; Franceschet, Cristian; Gamboa Lerena, Martin Miguel; Garcia, Beatriz; Garrido, Xavier; Gaspard, Michel; Gault, Amanda; Gayer, Donnacha; Gervasi, Massimo; Giard, Martin; Giraud Héraud, Yannick; Gómez Berisso, Mariano; González, Manuel; Gradziel, Marcin; Grandsire, Laurent; Guerard, Eric; Hamilton, Jean Christophe; Harari, Diego; Haynes, Vic; Henrot Versillé, Sophie; Hoang, Duc Thuong; Holtzer, Nicolas; Incardona, Federico; Jules, Eric; Kaplan, Jean; Korotkov, Andrei; Kristukat, Christian; Lamagna, Luca; Loucatos, Sotiris; Louis, Thibaut; Lowitz, Amy; Lukovic, Vladimir; Luterstein, Raúl Horacio; Maffei, Bruno; Marnieros, Stefanos; Masi, Silvia; Mattei, Angelo; May, Andrew; McCulloch, Mark; Medina, Maria Clementina; Mele, Lorenzo; Melhuish, Simon J.; Montier, Ludovic; Mousset, Louise; Mundo, Luis Mariano; Murphy, John Anthony; Murphy, James David; O'Sullivan, Creidhe; Olivieri, Emiliano; Paiella, Alessandro; Pajot, Francois; Passerini, Andrea; Pastoriza, Hernan; Pelosi, Alessandro; Perbost, Camille; Perciballi, Maurizio; Pezzotta, Federico; Piacentini, Francesco; Piat, Michel; Piccirillo, Lucio; Pisano, Giampaolo; Polenta, Gianluca; Prele, Damien; Puddu, Roberto; Rambaud, Damien; Ringegni, Pablo; Romero, Gustavo E.; Salatino, Maria; Schillaci, Alessandro; Scóccola, Claudia G.; Scully, Stephen P.; Spinelli, Sebastiano; Stankowiak, Guillaume; Stolpovskiy, Michail; Suarez, Federico; Tartari, Andrea; Thermeau, Jean Pierre; Timbie, Peter; Tomasi, Maurizio; Torchinsky, Steve A.; Tristram, Matthieu; Tucker, Carole E.; Tucker, Gregory S.; Vanneste, Sylvain; Viganó, Daniele; Vittorio, Nicola; Voisin, Fabrice; Watson, Robert; Wicek, Francois; Zannoni, Mario; Zullo, Antonio (MDPI, 2019-01-23)
    In this paper, we describe QUBIC, an experiment that will observe the polarized microwave sky with a novel approach, which combines the sensitivity of state-of-the-art bolometric detectors with the systematic effects control ...
  • Detached eddy simulation of unsteady flow over a frontal cavity 

    Salunke, Samruddhi; Shinde, Suryapratap; Singh, Ishika; Sahoo, Devabrata; Vashishtha, Ashish (American Institute of Aeronautics and Astronautics, 2023)
    Frontal cavity consists of complex unsteadiness which causes bow shock instabilities when the body is moving at supersonic or hypersonic speed through a fluid. These complex unsteady flow fields are an important practical ...
  • Effects of freestream disturbances in front of spiked blunt nose at hypersonic flow 

    Vashishtha, Ashish; Khurana, Shashank; Callaghan, Dean; Nolan, Cathal (Council of European Aerospace Societies, 2021)
    The effects of high frequency slow and fast acoustic wave freestream disturbances are modelled in front of pulsating bow shock formed at spiked blunt nose in hypersonic flow. These disturbances are introduced as time-dependent ...
  • Numerical study of an aerospike nozzle in retropropulsion 

    Vashishtha, Ashish; Khurana, Shashank; Callaghan, Dean; Nolan, Cathal (Council of European Aerospace Societies, 2021)
    The primary motivation of this numerical study is to explore the feasibility of drag enhancement using aerospike nozzle for retropropulsion in hypersonic flow. An external expansion contoured aerospike nozzle with design ...
  • An Open-Source Testbed to Visualise ICS Cybersecurity Weaknesses and Remediation Strategies – A Research Agenda Proposal 

    Ó Briain, Diarmuid; Ekisa, Conrad; Kavanagh, Yvonne (IEEE, 2021-07)
    Industrial Control Systems (ICS) are responsible for the control of several processes in various critical infrastructure deployments ranging from energy, power and water utilities, to manufacturing sectors such as ...
  • The Internet in East Africa: a mixed methods study 

    Ó Briain, Diarmuid; Denieffe, David; Okello, Dorothy; Kavanagh, Yvonne (East African Journal of Science, Technology and Innovation, 2020)
    East Africa was the last major area of the world to gain access to the Internet when submarine fibre-optic cables landed at Mombasa, Kenya and Dar-es-Salaam, Tanzania in 2009. The region previously relied on satellite ...
  • Enabling models of Internet eXchange Points for developing contexts 

    Ó Briain, Diarmuid; Denieffe, David; Okello, Dorothy; Kavanagh, Yvonne (Elsevier, 2020-10-24)
    In 2009, fibre-optic cables landed on the East coast of Africa, the last major area of the world to be connected to the Internet triggering a decade of Internet development (Graham et al., 2015). During the same period, ...
  • Oblique Detonation Wave Control with O3 and H2O2 Sensitization in Hypersonic Flow 

    Vashishtha, Ashish; Panigrahy, Snehasish; Campi, Dino; Callaghan, Dean; Nolan, Cathal; Deiterding, Ralf (MDPI journals, 2022-06-04)
    This numerical study investigates the effects of adding a small amount of ignition promoters for controlling the wedge-induced oblique shock wave (OSW) to oblique detonation wave (ODW) transition in a premixed hydrogen–air ...
  • Particle Acceleration Through Coaxial Co-Flow Nozzles for Cold Spray Applications 

    Kumar Sharma, Amit; Vashishtha, Ashish; Callaghan, Dean; Nolan, Cathal; Bakshi, Srinivasan; Kamaraj, M.; Raghavendra, Ramesh (ITSC 2022 Thermal Spray Conference and Exposition, 2022)
    The present study numerically investigates the effectiveness of co-flowing nozzle for cold spray application. A convergent - divergent axi-symmetric nozzles have been simulated with high-pressure nitrogen flow. The particle ...
  • Study of direct gas injection into stagnation zone of blunt nose at hypersonic flow 

    Harmon, Peter; Vashishtha, Ashish; Callaghan, Dean; Nolan, Cathal; Deiterding, Ralf (American Institute of Aeronautics and Astronautics, 2021-07-28)
    Direct gas injection in the shocked or compressed region has importance in many applications from drag control to ignition and pressure gain combustion. This numerical study is focused on direct light gas injection into ...
  • Novel mechanism of instability control using tapered spike in hypersonic flow 

    Vashishtha, Ashish; Khurana, Shashank (American Institute of Aeronautics and Astronautics, 2021-08-02)
    A forward facing spiked blunt nose in high-speed flows is associated with pulsating flow behavior of varying amplitudes depending on spike-nose and length, the forebody geometry and flow conditions. A tapered spike has ...
  • Numerical investigation of detonation propagation through small orifice holes 

    Vashishtha, Ashish; Callaghan, Dean; Nolan, Cathal; Deiterding, Ralf (Sciendo, 2021)
    Seeking to better understand the physical phenomena underlying detonation wave propagation through small holes (especially the phenomenon of detonation re-initiation or its failure), we investigated the propagation of a ...
  • CFD-CRN Study of NOx formation in a high-pressure combustor fired with lean premixed CH4 / H2 - air mixtures 

    Vashishtha, Ashish; Yousefian, Sajjad; Goldin, Graham; Frojd, Karin; Jella, Sandeep; Bourque, Gilles; Monaghan, Rory F.D. (The American Society of Mechanical Engineers, 2021-01)
    The main motivation of this study is to investigate detailed NOx and CO formation in high-pressure dump combustor fired with lean premixed methane-air mixture using CFD-CRN hybrid approach. Further, this study is extended ...
  • Pulsating flow investigation for spiked blunt-nose body in hypersonic flow and its control 

    Vashishtha, Ashish; Khurana, Shashank (American Institute of Aeronautics and Astronautics, 2021-01)
    An aerospike, as a technique for drag reduction and heat transfer in high-speed flows, is associated with instabilities. To understand the pulsating flow behavior in front of forward facing spiked blunt nose, numerical ...

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