Simulation of Air Puff Tonometry Test Using Arbitrary Lagrangian–Eulerian (ALE) Deforming Mesh for Corneal Material Characterisation

Purpose: To improve numerical simulation of the non-contact tonometry test by using arbitrary Lagrangian-Eulerian deforming mesh in the coupling between computational fluid dynamics model of an air jet and finite element model of the human eye. Methods: Computational fluid dynamics model simulated impingement of the air puff and employed Spallart–Allmaras model to capture turbulence of the air jet. The time span of the jet was 30 ms and maximum Reynolds number was R e = 2.3 × 10 4 , with jet orifice diameter 2.4 mm and impinging distance 11 mm. The model of the human eye was analysed using finite element method with regional hyperelastic material variation and corneal patient-specific topography starting from stress-free configuration. The cornea was free to deform as a response to the air puff using an adaptive deforming mesh at every time step of the solution. Aqueous and vitreous humours were simulated as a fluid cavity filled with incompressible fluid with a density of 1000 kg/m3. Results: Using the adaptive deforming mesh in numerical simulation of the air puff test improved the traditional understanding of how pressure distribution on cornea changes with time of the test. There was a mean decrease in maximum pressure (at corneal apex) of 6.29 ± 2.2% and a development of negative pressure on a peripheral corneal region 2–4 mm away from cornea centre. Conclusions: The study presented an improvement of numerical simulation of the air puff test, which will lead to more accurate intraocular pressure (IOP) and corneal material behaviour estimation. The parametric study showed that pressure of the air puff is different from one model to another, value-wise and distribution-wise, based on cornea biomechanical parameters.

Simulation of Air Puff Tonometry Test Using Arbitrary Lagrangian-Eulerian (ALE) Deforming Mesh for Corneal Material Characterisation

Purpose: To improve numerical simulation of the non-contact tonometry test by using Arbitrary Eulerian-Lagrangian deforming mesh in the coupling between computational fluid dynamics model of an air jet and finite element model of the human eye. Methods: Computational fluid dynamics model simulated impingement of the air puff and consisted of 25920 wedge6 elements and employed Spallart-Allmaras model to simulate capture turbulence of the air jet. The time span of the jet wais 30 ms and maximum Reynolds number

Parallelization of an Unsteady ALE Solver with Deforming Mesh Using OpenACC

This paper presents a parallel, GPU-based, deforming mesh-enabled unsteady numerical solver for solving moving body problems by using OpenACC. Both the 2D and 3D parallel algorithms based on spring-like deforming mesh methods are proposed and then implemented through OpenACC programming model. Furthermore, these algorithms are coupled with an unstructured mesh based, implicit time scheme integrated numerical solver, which makes the full GPU version of the solver capable of handling unsteady calculations with deforming mesh. Experiments results show that the proposed parallel deforming mesh algorithm can achieve over 2.5x speedup on K20 GPU card in comparison with 20 OpenMP threads on Intel E5-2658 V2 CPU cores. And both 2D and 3D cases are conducted to validate the efficiency, correctness, and accuracy of the present solver.

Research and Application of Aeroelastic Analysis Based on Fluid-Structure Interaction

the origins and characteristics of linear and nonlinear aeroelasticity are analyzed.And the deforming mesh , fluid-structure coupling schemes, the design method of aerodynamic module and structure module interface are also analyzed. their advantages and disadvantages are Pointed out. Finally, several recommendations are given for the development orientation of aeroelasticity in the future.