HiPSTAR

The High-Performance Solver for Turbulence and Aeroacoustic Research (HiPSTAR) was developed as part of a Royal Academy of Engineering/EPSRC research fellowship. The full compressible Navier-Stokes equations are solved on general curvilinear coordinates, with the option of also solving curvilinear cylindrical coordinates. The structured, multi-block code is tailored to be particularly efficient for modern HPC systems by making a significant effort to minimize the memory requirement in light of severe bandwidth limitations imposed by current multi core architectures. The code includes the following features: i) highly optimized (wavenumber resolution) 4th-order accurate parallelized compact differences, ii) a spectral method for the spanwise or azimuthal direction (in the case of cylindrical coordinates enabling a state-of-the-art axis treatment that exploits parity conditions of individual Fourier modes), iii) ultra low-storage 4th-order Runge-Kutta time integration, iv) skew-symmetric splitting of the nonlinear terms, v) non-reflective characteristic boundary conditions, vi) characteristic interface conditions for the connection of blocks with metric discontinuities, vii) a time dependent immersed boundary method for the realization of complex and/or moving geometries, and viii) domain decomposition in the two finite-difference directions using an MPI parallelization. The parallel efficiency of HiPSTAR has been extensively tested on various computing platforms and production runs have to date been performed on 14,208 cores. In a CRAY centre of excellence project (http://www.hector.ac.uk/coe/pdf/HiPSTAR_OMP_Report.pdf), the code was converted to a hybrid OMP/MPI parallelisation, where the OMP parallelisation was applied to the direction in which the spectral method is employed.

For queries about this topic, contact Richard Sandberg.

Projects

Computational Fluid Dynamics of Compressor Blades Within a Gas Turbine Engine (HiPSTAR)

Richard Sandberg (Investigator), John Leggett

As modern engines become more and more efficient, the importance of understanding the finer details of the physics involved grows, if further gains are to be achieved. In such harsh enviroments, such as within a gas turbine engine, there are few means of studying them physicaly and we are left with little choice but to use super computers to model the flow.

Development of a novel Navier-Stokes solver (HiPSTAR)

Richard Sandberg (Investigator)

Development of a highly efficient Navier-Stokes solver for HPC.

Direct Numerical Simulations of transsonic turbine tip gap flow

Richard Sandberg (Investigator)

Direct Numerical Simulations are conducted of the transsonic flow through the tip gap at real engine conditions.

Eddy-resol?ving Simulation?s for Turbomachi?nery Applicatio?ns

Richard Sandberg (Investigator), Li-Wei Chen

Traditionally, the design of turbomachinery components has been exclusively accomplished with steady CFD, with Reynolds Averaged Navier-Stokes (RANS) models being the predominant choice. With computing power continuously increasing, high-fidelity numerical simulations of turbomachinery components are now becoming a valuable research tool for validating the design process and continued development of design tool.
In the current project, Direct Numerical Simulations (DNS) and other eddy-resolving approaches will be performed of turbomachinery components to establish benchmark data for design tools, and to investigate physical mechanisms that cannot be captured by traditional CFD approaches.

Effects of trailing edge elasticity on trailing edge noise

Richard Sandberg (Investigator), Stefan C. Schlanderer

This work considers the effect of trailing edge elasticity on the acoustic and hydrodynamic field of a trailing edge flow. To that end direct numerical simulations that are fully coupled to a structural solver are conducted.

Is fine-scale turbulence universal?

Richard Sandberg (Investigator), Patrick Bechlars

Complementary numerical simulations and experiments of various canonical flows will try to answer the question whether fine-scale turbulence is universal.

Jet noise

Richard Sandberg (Investigator), Neil Sandham

Direct numerical simulations are used to investigate jet noise.

Supersonic axisymmetric wakes

Richard Sandberg (Investigator)

Direct numerical simulations are used to shed more light on structure formation and evolution in supersonic wakes.

Towards biologically-inspired active-compliant-wing micro-air-vehicles

Richard Sandberg (Investigator), Sonia Serrano-Galiano

Despite a good knowledge of the physiology of bats and birds, engineering applications with active dynamic wing compliance capability are currently few and far between. Recent advances in development of electroactive materials together with high-fidelity numerical/experimental methods provide a foundation to develop biologically-inspired dynamically-active wings that can achieve "on-demand" aerodynamic performance. However this requires first to develop a thorough understanding of the dynamic coupling between the electro-mechanical structure of the membrane wing and its unsteady aerodynamics. In this collaborative initiative between the University of Southampton and Imperial College London, we are developing an integrated research programme that carries out high-fidelity experiments and computations to achieve a fundamental understanding of the dynamics of aero-electro-mechanical coupling in dynamically-actuated compliant wings. The goal is to utilise our understanding and devise control strategies that use integral actuation schemes to improve aerodynamic performance of membrane wings. The long-term goal of this project is to enable the use of soft robotics technology to build integrally-actuated wings for Micro Air Vehicles (MAV) that mimic the dynamic shape control capabilities of natural flyers.