• Mechanical, Aerospace and Civil Engineering
• Postgraduate
• Research degrees
• Research topics
• Current and recently completed research topics
  • Aerospace Engineering
  • Civil Engineering
  • Environmental Engineering
  • Management of Projects
  • Mechanical Engineering
  • Nuclear Engineering

• Related links
  • Research groups
  • Research centres
  • Expert groups

Project title: Development of a New, Multiple Pulsed Percussion Laser Drilling Mathematical Model

 

Other PhD projects in Mechanical Engineering

 

Percussion laser drilling is becoming more used over the conventional drilling techniques and other laser drilling techniques especially for the cooling hole drilling of aerospace engine components. However, some defects are commonly found during drilling with this technique which is contributing to the loss of accuracy in drilled holes. In order to achieve the best drilled holed quality, the optimal setting of the operating parameters for a specific requirement is extremely necessary. This study aims to develop an analytical model of laser percussion drilling which takes into account the recoil pressure exerting on the molten liquid surface, and the exothermic energy generated from oxidation of the liquid metal and O2 assist gas. The model developed is divided into three stages: heating, melting and vaporization with melt ejection due to recoil pressure and assist gas pressure. The analysis is based on transient heat conduction in solid and liquid regions with the appropriate boundary and initial conditions at the solid-liquid and liquid-vapour interfaces. Analytical solving of the problem gives the correlations among the laser intensity and other parameters which subsequently enable the prediction of the hole diameter, recast layer thickness and temperature profiles in the solid and liquid.

 

Fig 1. Stage 1: Temperature profile at the solid surface	Fig 2. Stage 2: Temperature profile in the liquid layer

 

Top of page