Turbine Vane External Heat Transfer. Volume 1: Analytical and Experimental Evaluation of Surface Heat Transfer Distributions with Leading Edge Showerhead Film Cooling

Progress in predictive design capabilities for external heat transfer to turbine vanes was summarized. A two dimensional linear cascade (previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils) was used to examine the effect of leading edge shower head film cooling on downstream heat transfer. The data were used to develop and evaluate analytical models. Modifications to the two dimensional boundary layer model are described. The results were used to formulate and test an effective viscosity model capable of predicting heat transfer phenomena downstream of the leading edge film cooling array on both the suction and pressure surfaces, with and without mass injection

Turbine airfoil film cooling

The experimental data obtained in this program gives insight into the physical phenomena that occur on a film cooled airfoil, and should provide a relevant data base for verification of new design tools. Results indicate that the downstream film cooling process is a complex function of the thermal dilution and turbulence augmentation parameters with trends actually reversing as blowing strength and coolant-to-gas temperature ratio varied. The pressure surface of the airfoil is shown to exhibit a considerably higher degree of sensitivity to changes in the film cooling parameters and, consequently, should prove to be more of a challenge than the suction surface in accurately predicting heat transfer levels with downsteam film cooling

The effects of leading edge and downstream film cooling on turbine vane heat transfer

The progress under contract NAS3-24619 toward the goal of establishing a relevant data base for use in improving the predictive design capabilities for external heat transfer to turbine vanes, including the effect of downstream film cooling with and without leading edge showerhead film cooling. Experimental measurements were made in a two-dimensional cascade previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils under contract NAS3-22761 and leading edge showerhead film cooled airfoils under contract NAS3-23695. The principal independent parameters (Mach number, Reynolds number, turbulence, wall-to-gas temperature ratio, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio) were maintained over ranges consistent with actual engine conditions and the test matrix was structured to provide an assessment of the independent influence of parameters of interest, namely, exit Mach number, exit Reynolds number, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio. Data provide a data base for downstream film cooled turbine vanes and extends the data bases generated in the two previous studies. The vane external heat transfer obtained indicate that considerable cooling benefits can be achieved by utilizing downstream film cooling. The data obtained and presented illustrate the interaction of the variables and should provide the airfoil designer and computational analyst the information required to improve heat transfer design capabilities for film cooled turbine airfoils

Analytical and Experimental Evaluation of the Heat Transfer Distribution over the Surfaces of Turbine Vanes

Three airfoil data sets were selected for use in evaluating currently available analytical models for predicting airfoil surface heat transfer distributions in a 2-D flow field. Two additional airfoils, representative of highly loaded, low solidity airfoils currently being designed, were selected for cascade testing at simulated engine conditions. Some 2-D analytical methods were examined and a version of the STAN5 boundary layer code was chosen for modification. The final form of the method utilized a time dependent, transonic inviscid cascade code coupled to a modified version of the STAN5 boundary layer code featuring zero order turbulence modeling. The boundary layer code is structured to accommodate a full spectrum of empirical correlations addressing the coupled influences of pressure gradient, airfoil curvature, and free-stream turbulence on airfoil surface heat transfer distribution and boundary layer transitional behavior. Comparison of pedictions made with the model to the data base indicates a significant improvement in predictive capability

The Economics of Litigation and Arbitration: An Application to Franchise Contracts

If we define the deterrence benefits from contract enforcement as avoided harms net of avoidance costs, we should expect contracting parties to choose the dispute resolution forum that provides the greatest difference between deterrence benefits and dispute resolution costs for every type of dispute. We apply this general framework to franchise contracts and conduct an empirical analysis of the determinants of arbitration agreements among franchising parties. Although it is obvious that contracting parties have an incentive to choose arbitration in order to reduce dispute-resolution costs, there have been no studies of the importance of deterrence concerns. We examine the deterrence hypothesis here and find a great deal of support for it. Indeed, our results suggest that deterrence factors generally outweigh litigation costs in the design of dispute resolution agreements. We find that the probability of arbitration is significantly higher when the parties are likely to rely on implicit contract terms for governance and compliance with those terms is difficult to ensure

Examining A Decade Of Named Marketing Chairs In The United States

Named chairs in the academic field of marketing are examined for ten years providing time series and cross-sectional analysis to determine a profile of their personal characteristics and their schools

How a turn to critical race theory can contribute to our understanding of 'race', racism and anti-racism in sport

As long as racism has been associated with sport there have been consistent, if not coordinated or coherent, struggles to confront its various forms. Critical race theory (CRT) is a framework established to challenge these racialized inequalities and racism in society and has some utility for anti-racism in sport. CRT's focus on social justice and transformation are two areas of convergence between critical race theorists and anti-racists. Of the many nuanced and pernicious forms of racism, one of the most obvious and commonly reported forms of racism in sport, racial abuse, has been described as a kind of dehumanizing process by Gardiner (2003), as those who are its target are simultaneously (re)constructed and objectified according to everyday myth and fantasy. However, this is one of the many forms of everyday racist experiences. Various forms of racism can be experienced in boardrooms, on television, in print, in the stands, on the sidelines and on the pitch. Many times racism is trivialized and put down as part of the game (Long et al., 2000), yet its impact is rarely the source of further exploration. This article will explore the conceptualization of 'race' and racism for a more effective anti-racism. Critical race theory will also be used to explore the ideas that underpin considerations of the severity of racist behaviour and the implications for anti-racism. © The Author(s) 2010

Characteristics Of Accounting Faculty In The U.S.

In this article, the academic and personal characteristics of Accounting faculty members at Colleges and Universities in the United States are analyzed to determine the demographics of the Accounting Professorate. Data on 12 variables were collected for the 2004-2005 academic year as a means of constructing a professional profile of the typical accounting professor teaching at todays universities. Given that there are anticipated shortages of accounting faculty, this information should be of interest to students who are considering accounting as a major, those contemplating entering the profession, and those faculty members who are engaged in educating the next generation of accounting faculty members

The Three-Legged Stool of Voter Engagement

Disparities in voter turnout have increased significantly over the past four decades. Members of historically oppressed groups, those who are low-income, and or who have lower levels of education vote at significantly lower rates than white, wealthy and or more educated community members. These disparities correlate directly to political power and the eventual allocation of resources by elected officials. Therefore, eliminating these disparities through targeted voter engagement with client groups is particularly important for the profession of social work. This article describes the conceptualization of voter engagement as a three-legged stool, consisting of voter registration, regular voting, and basing voting decisions on self-interest. Without attention to all three legs, the potential for generating political power collapses, resulting in minimal influence on elected officials