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Several applications were carried out in order to validate the method presented in Part I. In Part II, two examples of these applications are presented; one relating to the aeroacoustics of the axial fans and the other one to the interaction impeller-volute tongue in a centrifugal pump. The test benches used to study the behavior of these machines are presented. The study of the fan was capable of quantifying the discrete noise associated with the fluctuations in pressure linked to the potential flow. The analysis of the centrifugal pump permitted comparing the theoretical pressure fluctuations with experimental ones measured by various unsteady pressure sensors placed on the impeller shroud and in the volute. The qualitative and quantitative results obtained confirm the interest and the range of the developed algorithm. [DOI: 10.1115/1.1399287]

An algorithm using the singularity method was developed. It allows taking into account the interaction between fixed and mobile cascades. Its principle is based on the summation of discrete vortices distributed periodically on the rotor and stator profiles. The overall matrix, obtained by applying the boundary conditions, takes into account the complexity of the studied cascade geometry (presence or not of splitter blades, possibly variable pitch of the profiles, etc...) To illustrate the interest and the impact of the algorithm, two parametric studies on turbomachines cascade are presented: Planes cascade made up of a rotor and a stator (at the mean radius of an axial fan). Circular cascade made up of impeller and a volute (peripheral cascade of a centrifugal pump). [DOI: 10.1115/1.1399286]

Transition characteristics of a boundary layer on a NACAO012 airfoil are investigated by measuring unsteady velocity using hot wire anemometry. The airfoil is installed in the incoming wake generated by an airfoil aligned in tandem with zero angle of attack. Reynolds number based on the airfoil chord varies from 2.0 X l0(super 5) to 6.0 X 10(super 5); distance between two airfoils varies from 0.25 to 1.0 of the chord length. To measure skin friction coefficient identifying the transition onset and completion, an extended wall law is devised to accommodate transitional flows with pressure gradient and nonuniform inflows. Variations of the skin friction are quite similar to that of the fiat plate boundary layer in the uniform turbulent inflow of high intensity. Measured velocity profiles are coincident with families generated by the modified wall law in the range up to y(super +) = 40. Turbulence intensity of the incoming wake shifts the onset location of transition upstream. The transitional region becomes longer as the airfoils approach one another and the Reynolds number increases. The mean velocity profile gradually varies from a laminar to logarithmic one during the transition. The maximum values of rms velocity fluctuations are located near y(super +) = 15-20. A strong positive skewness of velocity fluctuation is observed at the onset of transition and the overall rms level of velocity fluctuation reaches 3.0-3.5 in wall units. The database obtained will be useful in developing and evaluating turbulence models and computational schemes for transitional boundary layer.

Analyses of gas turbine plant performance, including the effects of turbine cooling, are presented. The thermal efficiencies are determined theoretically, assuming air standard (a/s) cycles, and the reductions in efficiency due to cooling are established; it is shown that these are small, unless large cooling flows are required. The theoretical estimates of efficiency reduction are compared with calculations, assuming that real gases form the working fluid in the gas turbine cycles. It is shown from a/s analysis that there are diminishing returns on efficiency as combustion temperature is increased; for real gases there appears to be a limit on this maximum temperature for maximum thermal efficiency. [DOI: 10.1115/1.1370156]

A simple, yet useful algorithm is developed to generate tool paths with global interference checking for five-axis point milling of turbomachinery components. Based on the projected distance between the surface data and the cutter-axis of a cylindrical ball-end mill, interference between the surface of a workpiece and the cutter can be detected. Given the cutter contact points of the surface and the cutter's size, it can produce the cutter location data without incurring interference through relatively rotating and tilting the workpiece. Applications of the developed procedure to five-axis machining of centrifugal compressor impellers with 13 and 15 blades are illustrated to demonstrate the usefulness and reliability of the approach. [DOI: 10.1115/1.1340639]

Turbo product codes (TPCs) provide an attractive alternative to recursive systematic convolutional (RSC)-based turbo systems. Rather than employ trellis-based decoders, an algebraic decoder may be repeatedly employed in a low-complexity, soft-input/soft-output errors-and-erasures decoder such as the Chase algorithm. Taking motivation from efficient forced erasure decoders, this implementation re-orders the Chase algorithm's repeated decodings such that the inherent computational redundancy is greatly reduced without degrading performance. The result is a highly efficient Fast Chase implementation; the algorithm presented here is principally applicable to single error-correcting codes although consideration is also given to the more general case. The new decoder's value in practical turbo schemes is demonstrated via application to decoding of the (64,57,4) extended Hamming TPC. Index Terms--Hamming codes, linear codes, MAP estimation, maximum-likelihood decoding, product codes.