Now showing items 1-10 of 10

    • 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 ...
    • Drag control by hydrogen injection in shocked stagnation zone of blunt nose 

      Vashishtha, Ashish; Callaghan, Dean; Nolan, Cathal (IOP Publishing, 2021)
      The main motivation of the current study is to propose a high-pressure hydrogen injection as an hybrid active flow control technique in order to manipulate the flow-field in front of a blunt nose during hypersonic flight. ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...