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This study aims to presenting an empirical model for partially admitted turbine efficiency. When the design mass-flow rate is too small that a normal full-admission design would give very-small blade height, it may be advantageous to use partial admission. The losses due to partial admission with long blades may be less than the losses due to leakage and low Reynolds-number of the full-admission turbines with short blades. The turbine efficiency is highly dependent on the degree of partial admission. The empirical model of turbine efficiency is necessary for simulation and analysis of dynamic performances of the turbine system. In this work, appropriate empirical loss correlations are introduced and a proper model is proposed for turbine efficiency.

Experimental and numerical tests are conducted to evaluate the proposed model and the results are compared with the results of existing models. In this work, the effect of nozzles overlapping on the flow pattern is emphasized. Therefore, various models with different degrees of overlapping are simulated and their effects on the turbine efficiency are subsequently evaluated.

A suitable cubic polynomial expression for small axial supersonic turbine efficiency in experiments is suggested. The overlapping nozzles cause change in the flow pattern and the entropy distribution. Therefore, any change in the degree of overlapping of nozzles changes the efficiency of the turbine.

In this work, time-consuming numerous experimental and numerical tests of the turbine are required.

Implication of a proper formula for a partially admitted turbine may result in enhanced prediction and dynamic performance evaluation of the test turbine.

A proper empirical model for a partially admitted supersonic turbine is introduced. This model is suitable for one blocked partially admitted turbine with Mach number between 1.2 and 1.8.

This paper aims to present the designing and investigating various types of impulse blade profiles to find the optimal profile that has better performance than the first or original blade. The studied model is a turbine with an output power below 1 MW and a large pressure ratio up to 20, which is used to gain relatively high specific work output. As a result of its low mass flow rate, the turbine is used under partial-admission conditions. The turbine’s stator is a group of convergence–divergence nozzles that provide supersonic flow.

More than 10 types of two-dimensional blade profiles were designed using the developed preliminary design calculations and numerical analysis. The numerical results are validated using the existing experimental results. Finally, the case with improved performance is introduced as the final optimum case.

It was found that the performance parameters such as efficiency, power and torque are increased by more than 8% in the selected best model, in comparison with the original model. Moreover, the total pressure loss is 12% decreased for the selected model. Finally, the selected profile with superior performance is proposed.

Simultaneous numerical tests are conducted to examine the interaction of different supersonic blade profiles with the partially injected flow to the rotor.

This paper is concerned with improving the flow pattern in the nozzle-rotor axial gap in impulse turbines using a genetic algorithm (GA) and 3D numerical analysis. The paper aims to discuss these issues.

The appropriate model was used to estimate the turbine performance introduced in the beginning of the work. Then, the nozzle design parameters that are effective in the axial gap flow pattern are optimized using a non-linear optimization code. This code works based on the GA theory. Since the GA results are not conclusive, the selected cases were evaluated using 3D numerical analysis. For a detailed comparison of the flow pattern in initial and improved cases, a transient analysis was done. Experimental tests were performed in order to validate the work. For this purpose, the characteristic curves of the turbines were studied and compared with each other.

Improving the nozzle-rotor axial gap flow pattern leading to increase in the total-to-total efficiency of the turbine by more than two points.

Partially injected flow forced to use the full model computational analysis.

Weight reduction in a feeding system.

New loss modeling method presented for partial admission condition.

ALTITUDE supercharging of aeroplane engines by means of turbo‐blowers driven by exhaust‐gas turbines differs from ordinary charging of internal combustion engines because the process is much more accentuated. Whilst the output of stationary engines can be increased by 50 per cent, that of rail‐car engines by 80 per cent, by supercharging, an aeroplane engine, to give its full output at 12,000 m. altitude, has to be supercharged so as to give four times its output without supercharging. Thus altitude supercharging offers certain peculiarities.

The purpose of this paper is to determine the role of evidence in the interviewing of suspects.

Analyses were made of 55 interview transcripts about the questioning of suspected sex offenders by officers of an Australian police service.

In 22 per cent of these interviews the suspect actively attempted to discover what the evidence against them was and in 9 per cent the interviewer attempted to learn of the suspect's knowledge of this evidence. Interviewers tended to favour a strategy of first asking the suspect to provide a free account of their role in the alleged crime. If this approach failed to elicit a confession, interviewers would then disclose at least some of the evidence against that suspect. In 93 per cent of the interviews some form of evidence disclosure was made by the interviewer; this was usually achieved by referring to the evidence indirectly rather than explicitly.

Although such disclosures of information seemed to have little impact on suspects' decisions to confess, this study illustrates the important role of evidence in the suspect interviewing process.

Suggests that the next civil supersonic passenger aircraft project will pose a number of challenges. The propulsion system for this aircraft will have to achieve economic operation for both supersonic and subsonic cruise modes. In addition, the current and intended noise and pollutant emissions legislation will have to be met. Suggests that, while there are a number of proposed engines for the next generation civil supersonic aircraft, they all exhibit difficulties in meeting the compromises inherent in the engine duty. Offers a novel solution based on a unique design. Discusses the underlying issues and presents the design based on retractable fans driven by a single stage double pass tip turbine.

Based on a lecture prepared as part of the celebration of Cranfield University's 50th anniversary. After briefly reviewing the early years, including Cranfield University's entry into this technology, discusses the nature of this industry, Some of the technology drivers, including environmental concerns, are examined to provide a background against which the development and the future of the industry can be considered. This is followed by a brief survey of some of the possible new civil aero gas turbine applications over the next 50 years, both the very likely and some curiosities. Finally, the changes that are likely to occur within the industry as a result of wider economic and political trends are considered, as well as the implications for those working within the industry. The development of the civil aero gas turbine has contributed, in large measure, to today's, US$ 300 billion civil aviation industry and is rightly seen as one of mankind's major engineering achievements. A single paper cannot do justice to this industry.