Numerical solution for the temperature distribution in a cooled guide vane blade of a radial gas turbine

A two dimensional finite difference numerical technique is presented to determine the temperature distribution of an internal cooled blade of radial turbine guide vanes. A simple convection cooling is assumed inside the guide vane blade. Such cooling has relatively small cooling effectiveness at the leading edge and at the trailing edge. Heat transfer augmentation in these critical areas may be achieved by using impingement jets and film cooling. A computer program is written in FORTRAN IV for IBM 370/165 computer

A two-dimensional finite-difference solution for the temperature distribution in a radial gas turbine guide vane blade

A two-dimensional finite difference numerical technique is presented to determine the temperature distribution in a solid blade of a radial guide vane. A computer program is written in Fortran IV for IBM 370/165 computer. The computer results obtained from these programs have a similar behavior and trend as those obtained by experimental results

TF34 engine compression system computer study

The stability of the fan and the compressor components was examined individually using linearized and time dependent, one dimensional stability analysis techniques. The stability of the fan core integrated compression system was investigated using a two dimensional compression system model. The analytical equations on which this model was based satisfied the mass, axial momentum, radial momentum, and energy conservation equations for flow through a finite control volume. The results gave an accurate simulation of the flow through the compression system. The speed lines of the components were reproduced; the points of instability were accurately predicted; the locations where the instability was initiated in the fan and the core were indicated; and the variation of the bypass ratio during flow throttling was calculated. The validity of the analytical techniques was then established by comparing these results with test data and with results obtained from the steady state cycle deck

Aerodynamic stability analysis of NASA J85-13/planar pressure pulse generator installation

A digital computer simulation model for the J85-13/Planar Pressure Pulse Generator (P3 G) test installation was developed by modifying an existing General Electric compression system model. This modification included the incorporation of a novel method for describing the unsteady blade lift force. This approach significantly enhanced the capability of the model to handle unsteady flows. In addition, the frequency response characteristics of the J85-13/P3G test installation were analyzed in support of selecting instrumentation locations to avoid standing wave nodes within the test apparatus and thus, low signal levels. The feasibility of employing explicit analytical expression for surge prediction was also studied

Exploration of mobile educational technology

Recent advances in mobile and wireless technology could be utilised to enhance the delivery of educational programmes. The use of this technology is known as “Mobile Education”. Mobile education technology provides unique opportunities for educators to flexibly deliver their educational material to learners via mobile services anywhere at any time. Moreover, the material delivered could be adapted to the learners’ needs and preferences. Examples of mobile devices which could be used in mobile education are handheld mobile devices such as laptops, cellular phones, ipods, personal digital assistants (PDAs), wireless classroom instantaneous feedback response systems and many others. This paper surveys recent in-roads made in this field of educational technology and its envisaged impact on electrical engineering students learning experience

Novel strategy for compensating current determination in single phase active power filters

This paper reports a novel strategy for analysing a single phase power system feeding A non-linear load. This strategy is based on a new theory to transform the traditional single phase power system into an equivalent two-axis orthogonal system. This system is based on complementing the single phase system with a fictitious second phase so that both of the two phases generate an orthogonal power system. This would yield a power system which is analogous to the three phase power system but with the phase shift between successive phases equal to pi/2 instead of 2pi/3. Application of this novel approach makes it possible to use the complex or Gauss domain analytical method in a similar way to the well known method of instantaneous reactive power for the three phase power system instigated by Akagi et al in 1984. Thus, for the fictitious two-axis phase power system, the concept of instantaneous active and reactive power could be instigated. Moreover, the concept of instantaneous power factor could be defined. The novel strategy of power system analysis outlined in this paper is applied to a single phase power system feeding a non-linear load in conjunction with an active power filter. The latter serves the purpose of compensating for either of the instantaneous reactive power or the harmonic current distortion in the single phase power system under investigation or for compensating of both. Experimental results demonstrated the effectiveness of the novel single phase power system analysis reported in this paper

Harmonic Distortion and Reactive Power Compensation in Single Phase Power Systems using Orthogonal Transformation Strategy

The orthogonal transformation technique which was instigated by Akagi et al in 1984 for the investigation of the instantaneous power in a three phase power system is extended in this paper in order to derive novel compensating current expressions for a single phase, shunt active power filter. This filter is used for a single phase power supply feeding a non-linear load in order to compensate for the instantaneous reactive power or the harmonic current distortion or for compensating of both. The configuration of the active power filter utilised in this investigation is included. In addition, the filter compensating current control technique and methods implemented for the evaluation of the filter ratings and size are included. An expression for the distortion power equation for a single phase power supply feeding a non-linear load is derived in the Appendix. This expression is extremely useful as an aid to design active power filters which compensate for both of the reactive power and the current higher harmonics. Experimental results demonstrated the effectiveness of the novel expressions for the active power filter compensating currents derived in this paper

Enhancement of the Dynamic Performance of Single Phase Active Power Filters Using Virtual Two Axis Strategy Publication

In this paper the orthogonal transformation technique or virtual two axis strategy which was instigated by Akagi et al in 1984 for three phase power systems has been extended by Dobrucky and Pokorny in 1999 for the determination of instantaneous power in single phase power systems. This technique is described in detail in two of the authors’ previous publications,[2] and [3], by adopting this technique, an expression for the reference current used in an active power filter for the compensation of harmonic distortion and reactive power is derived. This expression is implemented by a digital signal processor and results in providing an excellent transient response of the filter which is demonstrated experimentally. This excellent response is realized due to the fast evaluation of the filter reference current when the two axis strategy described in this paper is used

Flow behavior in inlet guide vanes of radial turbines

Scroll flow is discussed. Streamline pattern and velocity distribution in the guide vanes are calculated. The blade surface temperature distribution is also determined. The effects of the blade shapes and the nozzle channel width on the velocity profiles at inlet to the guide vanes are investigated