THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS COMPUTATIONS OF FILM COOLING FOR THE LEADING EDGE REGION OF A TURBINE BLADE MODEL

ABSTRACT Computations of film cooling are presented based on the geometry of a UBC experimental turbine blade model. This model has a semi-circlar leading edge with four rows of laterally-inclined film cooling orifices positioned symmetrically about the stagnation line. The computational domain follows the physical domain and includes the curved blade surface as well as the coolant regions in the circular coolant orifices. The injection orifices are inclined spanwise at 30 0 to the blade surface. A multi-zone curvilinear grid is used to simulate the complex configuration. Grids are generated by a block-structured elliptic grid generation method which represents exactly the curved blade surface as well as the circular injection orifices. Computations over the cooled turbine blade model are carried out for overall mass flow ratios of 0.52 and 0.97. The relative mass flow ratios from each orifice are specified to match experimental values. Density ratios of coolant to free stream were taken to be unity (constant density). Comparison of predicted film cooling effectiveness with experimental data showed reasonable agreement

Mathematical modelling of black liquor recovery boilers

"December, 1991."Part 2 also called: Report, mathematical modelling of black liquor recovery boilers

Multiple Jets in a Crossflow: Detailed Measurements and

ABSTRACT The fluid mechanics and heat transfer characteristics of film cooling is three-dimensional and highly complex. To better understand this problem, an experimental study was conducted in a low speed wind tunnel on a row of six rectangular jets injected at 900 to the crossflow (main stream flow). The jet-tocrossflow velocity ratios (blowing ratios) examined were 0.5, 1.0, and 1.5, and the jet spacing-to-jet width ratio was 3.0. No significant temperature difference between jet and crossflow air was introduced. Mean velocities, and six flow stresses were measured using a three-component laser Doppler velocimeter operating in coincidence-mode. Seeding of both jet and crossstream air was achieved with a commercially available smoke generator. Flow statistics are reported in the form of vector plots, contours, and x-y graphs, showing velocity, turbulence intensity, and Reynolds stresses. To complement the detailed measurements, flow visualization was accomplished by transmitting the laser beam through a cylindrical lens, thereby generating a narrow, intense sheet of light. Jet air only was seeded with smoke, which was illuminated in the plane of the light sheet. Therefore, it was possible to record on video tape the trajectory and penetration of the jets in the crossflow. Selected still images from the recordings are presented. Numerical simulations of the observed flow field were made by using a multi-grid, segmented, k-E CFD code. Special near wall treatment included a non-isotropic formulation for the effective viscosity, a low Re model for k, and an algebraic model for the length scale. Comparisons between the measured and computed velocities show good agreement for the non-uniform mean flow at the jet exit plane. Velocities and stresses on the jet centerline downstream of the orifice are less well predicted, probably because of inadequate turbulence modeling, while values off the centerline match those of the experiments much more closely

Black liquor combustion validated recovery boiler modeling. Final year report : a summary report of the project

"August 1998."Includes bibliographical references.Work performed under contract no. DE-FG07-90CE40936."DE-FG07-90CE40936."Prepared for the U.S. Department of Energy Office of Industrial Technologies by the Institute of Paper Science and Technology, Oregon State University, University of British Columbia,and Babcock & Wilcox Company