Tim Persoons

Learn More
Both vapour and gas bubbles are known to significantly increase heat transfer rates between a heated surface and the surrounding fluid, even with no phase change. However, the complex wake structures means that the surface cooling is not fully understood. The current study uses high speed infra-red thermography to measure the surface temperature and(More)
The exploitation of flow pulsation in microand mini-channels is a potentially useful technique for enhancing cooling of high-end photonics and electronics systems. It is thought that pulsation alters the thickness of the hydrodynamic and thermal boundary layers, and hence affects the overall thermal resistance of the heat sink. Although the fluid mechanics(More)
USP dissolution Apparatus 4 can have a pulsing or non-pulsing flow, with most commercial apparatus employing a pulsing flow. Overall, a low velocity flow field is present, particularly in the larger 22.6-mm diameter cell. Dissolution data, computational fluid dynamics (CFD), and imaging methods are used and discussed to investigate the effects of low(More)
Accurate mechanistic modelling of a complex system requires insight into the process being simulated, in addition to a theoretical 'first-principles' approach. The current work uses a numerical mechanistic model to simulate dissolution of a particulate system in the flow-through dissolution apparatus. A shadowgraph imaging method is also used to monitor the(More)
The dynamic velocity range of particle image velocimetry (PIV) is determined by the maximum and minimum resolvable particle displacement. Various techniques have extended the dynamic range, however flows with a wide velocity range (e.g., impinging jets) still challenge PIV algorithms. A new technique is presented to increase the dynamic velocity range by(More)
 We identify technological drivers for tomorrow’s data centers and telecommunications 14 systems, including thermal, electrical and energy management challenges, based on discussions at the 15 2nd Workshop on Thermal Management in Telecommunication Systems and Data Centers in Santa Clara, 16 California, on April 25-26, 2012. The relevance of thermal(More)
Synthetic jets are a relatively new technology and have shown great promise in a number of practical applications such as flow control through active boundary layer mixing and enhanced heat transfer through forced convection. It has been shown by Kercher et al. (2003) that synthetic jets can deliver similar cooling effects to conventional steady flow(More)
An impinging synthetic jet can attain heat transfer rates comparable to a continuous jet, without net mass input. However it needs a forced cross-flow to supply fresh cooling medium. The vectoring effect of adjacent synthetic jets allows directing the flow by changing the phase between the jets. This study uses the vectoring effect of two adjacent synthetic(More)
Impinging synthetic jets have been identified as a promising technique for obtaining high convective heat transfer rates in applications with confined geometries such as electronics cooling. Using a partially enclosed cavity with orifice, alternating fluid suction and ejection generate a periodic vortex train. This flow creates stronger entrainment of(More)