Experimental measurements and CFD predictions of blade water coverage in a diesel turbocharger

To be completed later</p

Bimetallic PtFe nano-particle fuel cell electrocatalyst for direction methanol fuel cell

Bimetallic Pt-Fe nano-particle alloy has been investigated to study their catalytic performance.</p

Measurement and prediction of water coverage of blade ring in a turbocharger

See published paper</p

Predicting film cooling performance of trailing–edge cutback turbine blades by detached–eddy simulation

The cooling efficiency of blade has been investigated using CFD approach with detached-eddy method</p

Comparison study of turbine blade with trailing-edge cutback coolant ejection designs

This paper investigates a turbine blade with two trailing-edge cutback coolant ejection designs, aiming for a comparison study of aerothermal performances such as discharge coefficient and film cooling effectiveness due to trailing-edge geometry change. Steady Reynolds-averaged Navier-Stokes (RANS) and two-equation turbulence models are adopted and numerical studies are carried out by two-stage investigations:- firstly, validation of an existing cutback blade model (i.e., half a blade model with pressure-side geometry only) that has been extensively studied experimentally and numerically by other researchers and predicted internal passage discharge coefficient and film cooling effectiveness along cutback surface are compared to experimental measurements; secondly, exploration of a more realistic blade model with full trailing-edge cutback geometry to understand possible performance changes due to new model design. It was found that steady RANS modelling are able to produce discharge coefficients and wall pressure distributions in fairly good agreement with test data, but not the film cooling effectiveness on cutback surfaces which under-predicts in near-field wake region, and over-predicts in far-field wake region. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.</p

Numerical simulation of laminar circular and noncircular jets in cross–flow

Direct numerical simulations have been performed to investigate the complex process of three-dimensional flow interactions around square, round and elliptic jets injected normally into the cross-flow mainstream. The velocity ratio of the jet to that of the cross-flow is 2.5 and the Reynolds number based on the free stream quantities and the jet exit diameter is 225. The main objective of this study is to assess the effect of the hole exit geometry on the dynamics of large-scale structures in jets cross-flow interactions. The computer code uses a finite-difference methodology, which solves the compressible three-dimensional unsteady Navier-Stokes and total energy equations in the Cartesian coordinate system. The obtained results reveal that, for all cases of hole geometry, the near field of the jet is dominated by the large-scale dynamic structures of complex flow nature. These flow structures undergo several interaction mechanisms and processes including reconnecting and pairing phenomena. The identified structures include the counter rotating vortex pair (CRVP), the Kelvin-Helmholtz roll-up of the jet shear layer vortices and the horseshoe vortex system. Our results also show that the jet lift-off as well as the cross-flow entrainment into the near wall regions mechanisms depend on the hole geometry. The maximum jet lift-off is found in the elliptic hole geometry case. These findings are in good agreement with existing experimental observations qualitatively.</p

Numerical simulation of a turbulent flow over an axisymmetric hill

To be completed later</p

Numerical study of unsteady airflow phenomena in a ventilated room

Numerical simulation of airflow in an indoor environment has been carried out for forced, natural, and mixed convection modes, respectively, by using the computational fluid dynamics (CFD) approach of solving the Reynolds-averaged Navier?Stokes equations. Three empty model rooms in two-dimensional configuration were studied first; focusing on the effects of grid refinement, mesh topology, and turbulence model. It was found that structured mesh results were in better agreement with available experimental measurements for all three convection scenarios, while the renormalized group (RNG) ? ? ? turbulence model produced better results for both forced and mixed convections and the shear stress transport (SST) turbulence model for the natural convection prediction. Further studies of air velocity and temperature distributions in a three-dimensional cubic model room with and without an obstacle have shown reasonably good agreement with available test data at the measuring points. CFD results exhibited some unsteady flow phenomena that have not yet been observed or reported in previous experimental studies for the same problem. After analyzing the time history of velocity and temperature data using fast Fourier transformation (FFT), it was found that both air velocity and temperature field oscillated at low frequencies up to 0.4 Hz and the most significant velocity oscillations occurred at a vertical height of an ankle level (0.1 m) from the floor, where temperature oscillation was insignificant. The reasons for this flow unsteadiness were possibly a higher Grashof number, estimated at 0.5 × 106 based inflow conditions, and thus strong buoyancy driven effects caused the oscillations in the flow field. The appearance of an obstacle in the room induced flow separation at its sharp edges and this would further enhance the oscillations due to the unsteady nature of detached shear-layer flow.</p

Comparison study of turbine blade with trailing–edge cutback coolant ejection designs

This paper investigates a turbine blade with two trailing-edge cutback coolant ejection designs, aiming for a comparison study of aerothermal performances such as discharge coefficient and film cooling effectiveness due to trailing-edge geometry change.</p

Evaluation of wall heat transfer in turbine blade trailing-edge passage

to be completed later</p