• Fun Facts

    Post
    Australians are exposed to 2 millisieverts of 'background' radiation per year
    Post
    A CT of the chest can be roughly equivalent to having 100 single chest X-rays
    Post
    15x Melbourne → Singapore → London flights exposes you to 1 millisievert
  • Diagnostic X-rays

    A diagnostic X-ray is the oldest and most common medical radiology procedure. Radiologists use X-rays to help diagnose disease or injury inside your body. A machine directs a small, carefully calculated amount of radiation toward a specific part of the body to produce an image on a film on the other side of the body. Radiologists study the X-ray images to detect and diagnose disease or injury.

  • CT dosage

    Computed Tomography (CT) is currently one of the major contributors to the collective population radiation dose due to the increasing popularity of CT examinations as a non-invasive diagnostic tool. The evolution of CT scanner technology has turned their use from specialized into routine examination. More due diligence is required due to the high radiation dose of CT.

  • Where to from here?

    It is of the utmost importance that both clinical justification as well as technical optimization are implemented to maintain a high benefit to risk ratio. Solid interdisciplinary partnerships and research endeavours between clinical specialists and technology engineers will help to fast track developments in this area.

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LDI Alumni Profile

photo-vaibhav

Vaibhav Kumar

Past FYP student; Completed LDI imaging project


Dept. Mechanical & Aerospace Engineering, Monash University Clayton Campus

Supervisors: Associate Professor Andreas Fouras

Vaibhav first joined LDI as a Summer Research Project student in November 2008 and completed his Final Year Project (FYP) as a 4th year undergraduate student in 2009. With success from his FYP, Vaibhav continued studying jet shock cells and surface topography with LDI postgraduate student Ivan Ng, leading to a series of publications (listed below). Vaibhav is currently undertaking postgraduate studies at Stanford University, USA.

Qualifications:

BAeroEng (Hons) Monash 2010, BCom (Management) Monash 2010

LDI Awards:

  • The Visualization Society of Japan (VSJ) Award for Excellent Visualization in 2011, for Surface Topography of Jet Shock Cells in an Hydraulic Analogy. Journal of Visualisation, 13(3), 175–176, doi: 10.1007/s12650-010-0032-3

LDI project topic:

Determining flow properties in the near-field of a supersonic jet nozzle exit using a hydraulic analogy

LDI project details:

The flow behind jet nozzles has been of great interest due to its effects on the aerodynamics, structure and propulsion system of an aircraft. The first shock cells at the exit of an underexpanded jet provide valuable information about the flow properties, such as pressure variations, acoustic vibrations, viscous effects, etc. A thorough understanding of the velocity flow field and pressure distribution at the nozzle exit can assist in various studies, such as the investigation of screech, which is an aeroacoustic phenomenon potentially harmful for aircraft structures. This study examines the flow regime more closely to assist in the development of more appropriate screech control mechanisms and more efficient propulsion systems.

The fundamental approach employed in this study is Particle Image Velocimetry, in which two subsequent images are compared to calculate the instantaneous displacement and velocity. A reference image can be compared with its distorted version, producing apparent displacement vectors to reconstruct the surface topography of water flow. Hydraulic flow on a water table is used as an analogy for supersonic air flow. Inherently, this is a simple, cost-effective and highly accurate technique.

LDI Publications:

  1. Kumar, V., Ng, I., Sheard, G.J., Brocher, E., Hourigan, K. & Fouras, A. (2011) Application of Particle Image Velocimetry and Reference Image Topography to jet shock cells using the hydraulic analogy. Experiments in Fluids, 51(2), 543–551.
    doi: 10.1007/s00348-011-1072-8
  2. Ng, I., Kumar, V., Sheard, G.J., Hourigan, K. & Fouras, A. (2011) Experimental study of simultaneous measurement of velocity and surface topography: In the wake of a circular cylinder at low Reynolds number. Experiments in Fluids, 50(3), 587–595.
    doi: 10.1007/s00348-010-0960-7
  3. Ng, I., Kumar, V., Sheard, G.J., Hourigan, K. & Fouras, A. (2010) Surface Topography of Jet Shock Cells in an Hydraulic Analogy. Journal of Visualisation, 13(3), 175–176.
    doi: 10.1007/s12650-010-0032-3

LDI Conferences:

  1. PDF Download Kumar, V., Ng, I., Sheard, G.J., Hourigan, K. & Fouras, A. (2009) Hydraulic Analogy Examination of Underexpanded Jet Shock Cells using Reference Image Topography, in Proc. 8th International Symposium on Particle Image Velocimetry — PIV09, Melbourne, Australia, 25–28 August 2009.
  2. PDF Download Ng, I., Kumar, V., Sheard, G.J., Hourigan, K. & Fouras, A. (2009) Experimental study of instantaneous measurement of velocity and surface topography in a wake of the circular cylinder at low Reynolds number, in Proc. 8th International Symposium on Particle Image Velocimetry — PIV09, Melbourne, Australia, 25–28 August 2009.

Teaching experience at Monash University:

  • Tutor: MAE3404 Flight vehicle dynamics, Monash University Clayton (2010)
  • Tutor: ENG1060 Computing for Engineers, Monash University Clayton (2008 & 2010)
  • Tutor: ENG1040 Engineering Dynamics, Monash University Clayton (2008)