Chi-Yao Chang

Joyson Safety Systems · Inflator center

div class="section abstract"> A competent numerical prediction on automotive restraint systems relies on accurate inflator characteristics as input data, which are specified to gas species composition, mass, and energy flow rate. Due to the highly transient processes under extreme temperature conditions of inflator deployment, the determination of...

The feasibility of a recently developed eddy-resolving model of turbulence, termed as Very LES (Large-Eddy-Simulation), was tested by simulating the flow dynamics in two moving piston-cylinder assemblies. The first configuration deals with the compression of a tumbling vortex generated during the intake process within a cylinder with the square cro...

The feasibility of a recently developed eddy-resolving model of turbulence, termed as Very LES (Large-Eddy-Simulation), was tested by simulating the flow dynamics in two moving piston-cylinder assemblies. The first configuration deals with the compression of a tumbling vortex generated during the intake process within a cylinder with the square cro...

A numerical model describing the ballistic behavior of a commercially used initiator is presented in this article. This model was built on the principle of conservation of mass and energy in the multi-phase framework incorporated with multi-loaded conditions. After obtaining the information about the grain size distribution in each composite, a fix...

Computational Fluid Dynamics (CFD) is widely used to predict wind conditions for wind energy production purposes. However, as wind power development expands into areas of even more complex terrain and challenging flow conditions, more research is needed to investigate the ability of such models to describe turbulent flow features. In this study, th...

An effective methodology for CFD simulations of stratified atmospheric boundary layer flows is presented, based on the Poiseuille-type zero pressure gradient boundary layer. The concept of precursor inflow generation is applied in the scope of Reynolds Averaging Navier-Stokes (RANS) simulations, and combined with mean temperature control via explic...

The annual energy production of an existing wind farm including thermal stratification is calculated with two different methods and compared to the average of three years of SCADA data. The first method is based on steady state computational fluid dynamics simulations and the assumption of Reynolds-similarity at hub height. The second method is a w...

The Rio Grande do Sul state, in Southern Brazil, is one of the most favorable regions for wind energy exploitation. Therefore, we evaluate mesoscale model's short term (several days) high resolution simulations, analyzing the potential wind power at two levels, 50 and 150 m. We compare the results with a wind atlas study from the Brazilian Wind Ene...

The present work is concerned with the application of the PANS-ζ -f (Partially-Averaged Navier-Stokes) variable resolutionmodel by Basara et al. (AIAA J 49:2627–2636, 2011), formulated in conjunction with the universal wall treatment, to the process of generation and destruction of a tumbling vortex in a squarepiston compression machine (investigat...

The swirling flow in a tube with the outlet designed in the form of an orifice nozzle with centered and eccentrical openings, investigated experimentally by Grundmann et al. (2012), was studied computationally by employing Large Eddy Simulation (LES) method and a Hybrid LES/RANS (Reynolds-Averaged Navier–Stokes) method. The latter method, denoted b...

The present work deals with validation of the PANS (Partially-Averaged Navier-Stokes) computational methodology coupled with the ζ − f RANS model of turbulence [10], formulated and implemented into the CFD software package AVL-FIRE by Basara et al. [2], in a broad range of wall-bounded flows featured by separation, swirling and tumbling motion. The...

The present work is concerned with the comparative analysis of predictive capabilities of different hybrid LES/RANS methods formulated in both zonal and seamless frameworks employing advanced anisotropy-resolving RANS models (both eddy-viscosity and Reynolds stress transport model groups were investigated). The hybrid schemes include both seamless...