Title: Computational fluid dynamics analysis of the production of bio-thermal spray hydroxyapatite powders

Authors: Qasim Murtaza; Joseph Stokes; Malika Ardhaoui

Addresses: Materials Processing Research Centre (MPRC), Dublin City University, Dublin-9, Ireland; Delhi Technological University (formerly Delhi College of Engineering), Delhi-42, India. ' Materials Processing Research Centre (MPRC), Dublin City University, Dublin-9, Ireland. ' Materials Processing Research Centre (MPRC), Dublin City University, Dublin-9, Ireland

Abstract: Hydroxyapatite (HA) thermal spray powder for hip implant's coating may be produced via a mixed type spray drying technique. The HA thermal spray coating performance depends upon the quality of the starting HA powder. Production of this powder is based on a spray drying technique for its fast and continuous production since the HA slurry gets well dispersed in the drying medium through atomisation. This dispersal leads higher rate of evaporation per unit mass of HA product causing more extraction of water from the HA slurry. However, the quality of the powder produced by this spray drying method is low, with inconsistent morphologies and densities, properties that are required in the plasma deposition process. The objective of this study was to use the commercial CFD solver FLUENT to simulate the spray dryer so as to study the various controlling parameters in order to improve the quality of spray dried product. The simulation results predicted the particle size and thermal histories of powder as a result of changing the initial parameters such as HA slurry viscosity. Hence, it proved to be a useful method for understanding the dynamics of the spray drying technique and in optimising the spray drying process.

Keywords: hydroxyapatite; HA thermal spray; spray drying; computational fluid dynamics; CFD; bio-thermal spray powders; bioengineering; biomechanical engineering; hip implants; implant coating; simulation; slurry viscosity.

DOI: 10.1504/IJCMSSE.2012.049052

International Journal of Computational Materials Science and Surface Engineering, 2012 Vol.5 No.1, pp.31 - 54

Received: 28 Mar 2011
Accepted: 28 Oct 2011

Published online: 23 Aug 2014 *

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