Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Daniel Duke Project Name: XRayFuelSpray Division: ES Project title: Fuel Injection and Sprays Studied Using X-Ray Diagnostics Associated funding: DOE-EERE Other Systems: None Science: At the Advanced Photon Source Sector 7-BM at Argonne National Laboratory, we are presently engaged in an ongoing investigation of sprays in high pressure fuel injection systems using X-ray diagnostic techniques. An improved understanding spray formation physics is essential to the development of more efficient engine technology. As a part of this ongoing research, we are investigating the presence of cavitation phenomena in fuel injection systems and how these phenomena impact spray formation. Cavitation is a problem in fuel injection systems which operate under high pressure. At the Advanced Photon Source, we are undertaking a series of experiments to develop a novel methodology for measuring real-time cavitation inside fuel injection systems using advanced X-ray imaging techniques. A model nozzle and fuel injection system have been designed specifically for this purpose. In order to develop these novel experimental techniques, it is necessary to have an accurate and detailed prediction of the cavitation zones inside the model nozzle at precisely defined boundary conditions, so that the measurement may be compared against an accurate baseline. To achieve this, numerical simulations of the fluid flow are necessary. The prediction of cavitation in a turbulent flow at high pressure requires the use of a high-resolution three-dimensional mesh with high levels of local refinement. As such, the computation time for these highly resolved meshes is beyond the reasonable capability of a desktop computer. The Fusion cluster will allow us to make these computations. The availability of accurate and detailed prediction of cavitation zones in a model nozzle will permit the exposition of these new experimental techniques, which will enable the measurement of cavitation zones in fuel injection systems and lead to improved design for purpose to reduce or enhance local cavitation. Project description: Computational Fluid Dynamics using the OpenFOAM framework has been employed to simulate cavitating turbulent fluid flow in both simplified nozzles and diesel fuel injectors, with the purpose of supporting and informing x-ray radiography and phase-contrast measurements performed at the Advanced Photon Source. A number of state-of-the-art numerical solvers have been implemented in OpenFOAM; namely incompressible-liquid and fully compressible homogeneous relaxation cavitation models and more recently a noncondensible-gas fully compressible homogeneous relaxation cavitation model. These codes were developed by Schmidt et al at the University of Massachusetts-Amherst. In the last year, we have switched from using OpenFOAM’s built-in solvers for multiphase flow to a dedicated cavitation code (HRMFoam) developed by Professor David Schmidt. The homogeneous relaxation model (HRM) assumes that when vapor is present, the vapor and liquid are homogeneously mixed within the local cell, but are not at thermodynamic equilibrium. The equilibrium state is not computed using an equation of state but is instead determined from a lookup table formulated using NIST REFPROP data. The HRM model has successfully been employed to simulate the effect of varying gasoline-ethanol blended fuels in a cavitating polycarbonate nozzle, and the results were favorably compared to x-ray radiography measurements performed at the Advanced Photon Source. Further high-resolution large eddy simulations of the polycarbonate nozzles used at APS are need to be undertaken in the following year. Scalability of HRMFoam simulations is good up to approx. 72 processors (the capacity of our dedicated nodes). We need to run multiple simulations at various boundary conditions, thus the need for additional allocation beyond the use of the dedicated nodes. Several improved solvers are currently under development which over the next year will allow for the modeling of a non-condensible gas phase, to simulate the difference between a ‘submerged’ cavitating flow and a cavitating flow issuing into a gaseous environment, as is the case for fuel injection in engines. Compressible modeling is also being investigated through both HRM and also alternative compressible fluid solvers. Currently, HRM assumes the liquid phase to be incompressible. Although this has shown good results in comparison with experimental data, given the extremely high pressures involved in fuel injection (greater than 1500 bar) bulk compressibility of the fuel will not be insignificant. Further development is occurring within the OpenFOAM framework and we do not expect to need any additional software installed on Fusion to achieve these goals. Our allocation for the following year will need to be maintained at the current level to achieve the above goals. No increase in allocation is required. We expect that less than 1% of the allocation will be single-core jobs (of which most are file I/O and cleanup tasks at the start and end of parallel jobs). Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 500000 Q1: 125000 Q2: 125000 Q3: 125000 Q4: 125000 Justification: 6*12 processor dedicated nodes have been purchased on FUSION to support these studies. Thank You, The LCRC Accounts System