The present study explains a steady-state method of measuring convective heat transfer coefficient on the casing of an axial flow turbine. The goal is to develop an accurate steady-state heat transfer method for the comparison of various casing surface and tip designs used for turbine performance improvements. The freestream reference temperature, especially in the tip gap region of the casing,...

This paper presents a numerical study of the acoustic shielding of aeroengine noise by the aircraft structure. More specifically, the engines considered are contra-rotating open rotors in pusher mode which are installed at the rear of the aircraft. Several empennage designs and engine positions are evaluated. An original method for the calculation of engine noise installation effects is present...

Ultrasonic rotary motors have the potential to meet this NASA need and they are developed as actuators for miniature telerobotic applications. These motors are being adapted for operation at the harsh space environments that include cryogenic temperatures and vacuum and analytical tools for the design of efficient motors are being developed. A hybrid analytical model was developed to address a ...

The market for twin screw compressors is highly competitive, especially in compressed air and refrigeration systems, and new designs are continually being introduced which are more efficient and cost effective than their predecessors. However, because of the high cost of development of new machines, manufacturers seek to maintain their existing designs for as long as possible. Closer study of m...

This paper presents a stochastic, multi-parameters, divergence optimization method for the auto-tuning of proportional–integral–derivative (PID) controllers according to a fractional-order reference model. The study aimed to approximate the step response of the real closed-loop flight control system to the response of a theoretical reference model for a smoother and more precise flight control ...

Increasing demands for more efficient screw compressors require that compressor designs are tailored upon their duty, capacity and manufacturing capability. A suitable procedure for optimisation of the screw compressor shape, size, dimension and operating parameters is described here, which results in the most appropriate design for a given compressor application and fluid. It is based on a rac...

With an increase in renewable energy the electricity grid, more storage capacity for grid stabilization and flexibilization is necessary. Dynamic one possible application flywheels. To density of flywheels, they can be built as highly integrated outer rotor systems. The losses flywheel are reduced by magnetic levitation operation under vacuum conditions. In case failure or overload active beari...

terms of pre-selection of the aero layouts best suited for further optimization Abstract The first task within the STOW project was 'analytical – theoretical study in terms of pre-selection of the aero layouts best suited for further optimization' for universal Polish wind conditions. It was carried out by an extensive literature study on classic wind turbine configurations (two, tree –bladed h...

This research examines a chronic problem in academic settings – inappropriate copying or misuse of source materials–i.e., plagiarism. We conduct a computer-based writing experiment to examine the effects of psychological and situational characteristics on subjects’ propensity to misappropriate text. Specifically, we examine to what extent such misappropriations may be explained by available tec...

Using 3.3 pb of data collected with the CMD-2 detector in the 720 – 840 MeV c.m. energy range, the branching fraction of the conversion decay ω → πee has been measured: B(ω → πee) = (8.19 ± 0.71± 0.62) · 10. The upper limits for the branching fractions of the following conversion decays have been obtained at the 90% confidence level: B(ρ → πee) < 1.6 · 10, B(ρ → ηee) < 0.7 · 10 and B(ω → ηee) <...