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In order to improve the engine reliability and efficiency, an effective way is to reform the turbine blade tip conformation. The paper aims to discuss this issue.

The present research provides several novel tip-shaping structures, which are considered to control the blade tip loss. Four different tip geometries have been studied: flat tip, squealer tip, flat tip with streamwise ribs and squealer tip with streamwise ribs. The tip heat transfer and leakage flow are both analyzed in detail, for example the tip heat transfer coefficient, tip flow and local pressure distributions.

The results show that the squealer seal and streamwise rib can reduce the tip heat transfer and leakage loss, especially for the squealer tip with streamwise ribs. The tip and near-tip flow patterns at the different locations of axial chord reflect that both the squealer seal and streamwise rib structure can control the tip leakage flow loss. In addition, the analysis of the aerodynamic parameters (the static pressure and turbine efficiency) also indicates that the squealer tip with streamwise ribs obtains the highest adiabatic efficiency with an increase of 2.34 percent, compared with that of the flat tip case.

The analysis of aerothermal and dynamic performance can provide a reference for the blade tip design and treatment.

This paper aims to discuss the results of the performance study of wind turbine blades equipped with winglets. An investigation focusses on small wind turbines (SWTs), where the winglets are recalled as one of the most promising concepts in terms of turbine efficiency increase.

To investigate a contribution of winglets to SWT aerodynamic efficiency, a wind tunnel experiment was performed at Lodz University of Technology. In parallel, computational fluid dynamics (CFD) simulations campaign was conducted with the ANSYS CFX software to investigate appearing flow structures in greater detail.

The research indicates the potential behind the application of winglets in low Reynolds flow conditions, while the CFD study enables the identification of crucial regions influencing the flow structure in the most significant degree.

As the global effect on a whole rotor is a result of a small-scale geometrical feature, it is important to localise unveiled phenomena and the mechanisms behind their generation.

Even the slightest efficiency improvement in a distributed generation installation can promote such a solution amongst energy prosumers and increase their independence from limited natural resources.

The winglet-equipped blades of SWTs provide an opportunity to increase the device performance with relatively low cost and ease of implementation.

AT the end of the war in Europe, Germany had two aircraft jet engines in operational use; the Junkers Jumo 004, which has already been described, and the BMW 003 which forms the subject of this article. Compared with the Junkers 004 the BMW engine can be described as having gone one stage further in the development of the axial compressor engine, but production figures were not as great as those of the Junkers. Several hundred had been built, mainly for the Heinkel He 162 Volksjäger—the high‐speed fighter with the engine mounted over the fuselage. The engines made in the 003 series are the 003‐A0, ‐Al, ‐A2, ‐E1 and ‐E2. These are all similar and have much the same performance. The latest in this series, the 003‐A2, is shown in fig. 1, and although production was planned on a large scale, only a few of this type were actually made.

This paper aims to investigate the cycle performance of a small size turbojet engine used in unmanned aerial vehicles at 0–5,000 m altitude and 0–0.8 Mach flight speeds with real component maps.

The engine performance calculations were performed for both on-design and off-design conditions through an in-house code generated for simulating the performance of turbojet engines at different flight regimes. These calculations rely on input parameters in which fuel composition are obtained through laboratory elemental analysis.

Exemplarily, according to comparative results between in-house developed performance code and commercially available software, there is 0.25% of the difference in thrust value at on-design conditions.

Once the on-design performance parameters and fluid properties were determined, the off-design operation calculations were performed based on the compressor and turbine maps and scaling methodology. This method enables predicting component maps and fitting them to real conditions.

A method to be used easily by researchers on turbojet engine performance calculations which best fits to real conditions.

The purpose of this paper is to propose and develop artificially intelligent methodologies to discover degradation trends through the detection of engine’s status. The objective is to predict these trends by studying their effects on the engine measurable parameters.

The method is based on the implementation of an artificial neural network (ANN) trained with well-known cases referred to real conditions, able to recognize degradation because of two main gas turbine engine deterioration effects: erosion and fouling. Three different scenarios are considered: compressor fouling, turbine erosion and presence of both degraded conditions. The work consists of three parts: the first one contains the mathematical model of real jet engine in healthy and degraded conditions, the second step is the optimization of ANN for engine performance prediction and the last part deals with the application of ANN for prediction of engine fault.

This study shows that the proposed diagnostic approach has good potential to provide valuable estimation of engine status.

Knowledge of the true state of the engine is important to assess its performance capability to meet the operational and maintenance requirements and costs.

The main advantage is that the engine performance data for model validation were obtained from real flight conditions of the engine VIPER 632-43.

THIS paper is not intended to provide any startling revelations of Soviet technology but is a detailed survey and analysis of contemporary developments in Soviet turbine powered transport aircraft. The major portion of the work is based on Soviet sources of information in an attempt to assure authenticity and accuracy.

TO deliver a lecture in commemoration of the Wright Brothers before the Institute of Aeronautical Sciences is a great honour of which I am deeply aware: this honour one feels is due not solely to the technical situation but to somemore subtle link between the Institute and the Royal Aeronautical Society and our two countries.

THE performance of a gas turbine fuel can be estimated most conveniently by using a single combustion chamber test unit. Such fuel testing has often shown a lack of repeatability that is difficult to ascribe to normal experimental errors only. In reviewing possible sources of error, the uncontrolled variable of atmospheric humidity has been considered. From past records the average specific humidity in the British Isles is 0·006 lb. water per lb. of dry air while the maximum on any day is unlikely to exceed 0·020 lb. water per lb. of dry air.

A LOW‐POWER gas‐turbine engine developed by the Boeing Airplane Company and the reasons for its evolution were des‐cribed by S. D. Hage, chief of the company's propulsion development unit, at the annual meeting of the Society of Automotive Engineers in Detroit last January. When the U.S. Air Forces invited proposals late in 1943 for a medium bomber driven by high‐speed turbo‐jet engines, the development of gas turbines was in such an early stage that not enough practical information was available from manufacturers to meet the needs for designing an aircraft to take maximum ad‐vantage of this type of power‐plant, so Boeing decided to make a thorough study of the new engine type, developing one of small size to keep the cost of research as low as possible.

OPERATING to increasingly severe noise and NOx emission levels and at the lowest Specific Fuel Consumption (SFC) attainable, current turbofan engines represent considerable advances in all respects on powerplants of only a few years ago. Nevertheless, the demand for even larger engines has meant that the major manufacturers are making considerable efforts to develop operating cycles and improved components to attain optimum performance for the foreseeable future.