Kyoto University · Engineering
Professor Abhishek Lakshman Pillai's research lab specializes in computational fluid dynamics and combustion science, with a focus on spray combustion, turbulence, and combustion noise in advanced engine systems. The lab investigates fundamental mechanisms of heat transfer, flame-wall interactions, and instability phenomena in compression ignition and lean-premixed combustors using high-fidelity numerical simulations such as Large-Eddy Simulation (LES) and Direct Numerical Simulation (DNS). A key emphasis is placed on modeling multiphase reactive flows, radiative heat loss, and acoustic emissions in alternative fuel systems like hydrogen and ethanol. Additionally, the lab explores hardware-software co-design for embedded systems, particularly in optimizing VLIW processor architectures for performance, energy efficiency, and fault tolerance through runtime error detection strategies.
Figures are computed from collected data and may differ slightly.
Combustion instabilities occurring in spray combustion fields inside a backward facing step combustor have been investigated by performing large-eddy simulations (LES). In this study, the influence of fluctuations in the incoming oxidizer air velocity (caused by drastic pressure oscillations in the combustor during combustion instability) on the droplet diameter distribution (due to atomization) of the injected liquid fuel spray, as well as the influence of pressure oscillations on the fuel flow
Design of Compression Ignition (CI) engines with improved thermal efficiencies needs better understanding of the heat transfer mechanism from spray flame to the combustion chamber wall. In this regard, heat transfer occurring during the interaction between impinging spray flame and wall, under CI engine-like conditions, is investigated in this study using 3-Dimensional numerical simulations based on an Eulerian–Lagrangian framework. Simulations are performed for different fuel spray injection ve
An open lean-premixed hydrogen/air low-swirl (LPHALS) turbulent flame exhibiting a pronounced peak in its combustion noise spectra, is investigated numerically using a hybrid Computational Fluid Dynamics/Computational Aero-Acoustics (CFD/CAA) framework. Under this framework, the reacting flow-field of the flame is computed via Large-Eddy Simulation (LES), while the direct combustion noise it produces is captured by solving the Acoustic Perturbation Equations for Reacting Flows (APE-RF). Flame co
Research indicates that as technology scales, hard errors such as wear-out errors are increasingly becoming a critical challenge for microprocessor design. While hard errors in memory structures can be efficiently detected by error correction code, detecting hard errors for functional units cost-effectively is a challenging problem. In this paper, we propose to exploit the idle cycles of the under-utilized VLIW functional units to run test instructions for detecting wear-out errors without incre
Combustion noise generation from an open turbulent spray flame with Ethanol as the fuel is investigated using Direct Numerical Simulation (DNS). The multiphase reactive flow is simulated using an Eulerian/Lagrangian approach. The governing equations for the carrier gas phase are solved in an Eulerian framework, whereas the motions of the evaporating Ethanol droplets are tracked in a Lagrangian framework. A two-step global reaction mechanism is used to model Ethanol combustion. Two simulations ar
The number of functional units can have significant impact on both the performance and energy consumption of VLIW processors. This paper uses a design exploration approach to find optimal integer functional unit configurations for achieving the best EDP (energy delay product) results for different media applications. Our experimental results quantitatively indicate that the optimal number of integer functional units should match the instruction level parallelism that can be extracted from the ap
The applicability of Large-Eddy Simulation (LES) for analyzing the phenomenon of turbulent spray flame impinging on a wall, under compression ignition (CI) engine-like environment is assessed in this paper. The LES results are compared with those of Direct Numerical Simulation (DNS), and it is demonstrated that LES can be successfully applied for reproducing the characteristics of turbulent spray flame (such as ignition delay time, lift-off length, etc.) and its interaction with a wall upon impi
Dual instruction execution (DIE) is an effective instruction-level temporal redundancy technique to improve the datapath reliability against transient errors for superscalar microprocessors. However, previous study shows that the performance overhead of dual instruction execution on an out-of-order core is substantial, primarily due to the serious resource contention problems such as the ALU bandwidth. In this paper, we propose a novel approach to reducing the performance overhead of DIE without
Cranio-maxillofacial surgery is a surgical specialty that focuses on the reconstructive surgery of the entire cranio-maxillofacial complex: the anatomical area of the mouth, jaws, face, and skull, head and neck as well as associated structures.A highly precise and complex procedure, it demands a well-structured and comprehensive treatment planning process.Biomedical extended reality (XR) has proven to be beneficial in the pre-surgery visualization step as it enables interaction in the three-dime
The applicability of Large-Eddy Simulation (LES) for analysing the phenomenon of turbulent spray flame impinging on a wall, under Compression-Ignition (CI) engine-like environment is assessed. The fuel spray is n-dodecane whose turbulent combustion is modelled using a Non-Adiabatic Flamelet/Progress-Variable (NA-FPV) approach. LESs are based on a Eulerian-Lagrangian framework and the sigma sub-grid turbulence model is used to calculate the subgrid scale (SGS) turbulent viscosity. Dynamics of liq
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