This thesis presents a joint computational and experimental investigation into the heat transfer to unshrouded turbine blade tips suitable for use in high bypass ratio, large civil aviation turbofan engines. Both the heat transfer to the blade tip and the over-tip leakage flow over the blade tip are characterised, as each has a profound influence on overall engine efficiency.
The study is divided into two sections; in the first, computa ... [truncated at 450 characters in length]
|Creator||Brian M. T. Tang;|
|Subject||Aero engines Aerodynamics and heat transfer Turbomachinery hypersonics and aerodynamics Mechanical engineering Engineering & allied sciences|
|Abstract||This report reviews the definition and some of the properties of the Wigner-Ville distribution for both continuous and discrete signals. A digital computer program implementing the discrete Wigner-Ville distribution is described and its performance is demonstrated by the analysis in the time-frequency domain of a series of numerically-generated test signals, showing the form of the Wigner-Ville distribution and the interference terms which can be ... [truncated at 450 characters in length]|
|Author||P. D. McFadden; W. J. Wang;|
|Subject||Engineering & allied sciences Mechanical engineering|
The brain accounts for around 2 % of human adult bodyweight but consumes 20 % of the resting oxygen available to the whole body. The brain is dependent on a constant supply of oxygen to tissue, transported from the heart via the vasculature and carried in blood. An interruption to flow can lead to ischaemia (a reduced oxygen supply) and prolonged interruption may result in tissue death, and permanent brain damage.
The cerebral vasculatu ... [truncated at 450 characters in length]
|Subject||Engineering & allied sciences Biomedical engineering Mathematical modeling (engineering)|
It has been 20 years since the word ultrawideband (UWB) has first been used in the open literature. In these 20 years, ideas have been transformed into real products. Yet, some might object that UWB has not yet lived upto the promises of gigabit wireless. This review shows that despite some drawbacks, UWB is not only needed because of the spectrum gridlock but it can still deliver its promises, including gigabit wireless. To do so, the gap bet ... [truncated at 450 characters in length]
|Author||Vit Sipal; Ben Allen; David Edwards; et al|
|Subject||Engineering & allied sciences Communications engineering (optical,microwave and radio) Electrical engineering|
This letter considers and recommends OFDM with adaptive subcarrier modulation as a suitable candidate for wireless UWB communication in computer chassis. A rigorous measurement campaign studies the guaranteed spectral efficiency. It concludes that enhancement of the existing WiMedia OFDM systems with a bandwidth of 528 MHz in order to support adaptive OFDM would enable data-rates above 1 Gbps over short ranges, i.e. the spectral efficiency wou ... [truncated at 450 characters in length]
|Author||Vit Sipal; Javier Gelabert; Christopher J. Stevens; et al|
|Subject||Engineering & allied sciences Electrical engineering Communications engineering (optical,microwave and radio)|