Experimental study on the self-noise of a turbulent round jet investing a cambered aerofoil

This paper describes an experimental investigation of the interaction noise in a jet impacting isolated aerofoils. The authors conducted the study in a low-speed wind tunnel ending in an anechoic chamber, and focussed on the tip region of two types of isolated low speed axial fan cambered aerofoils. The authors set the Mach number, Reynolds number and blade incidence angles in a static frame of reference to reproduce a flow field condition kinematically similar to that in the rotating frame. They correlated far-field noise measurements with near-field pressure measurements which they took at different chord-wise positions in the blade’s tip region. The aim was to find, by means of a cross correlation technique, a causal relationship between the aerodynamic sources in the tip region and noise emissions in order to establish the role of aerofoil self-noise associated with turbulent structures which turbulent inflow and blade tip geometry interaction produced

Aerodynamic and mechanical performance of a high-pressure turbine stage in a transient wind tunnel

Unsteady three-dimensional flow phenomena have major effects on the aerodynamic performance of, and heat transfer to, gas-turbine blading. Investigation of the mechanisms associated with these phenomena requires an experimental facility that is capable of simulating a gas turbine, but at lower levels of temperature and pressure to allow conventional measurement techniques. This thesis reports on the design, development and commissioning of a new experimental facility that models these unsteady three-dimensional flow phenomena. The new facility, which consists of a 62%-size, high-pressure gas-turbine stage mounted in a transient wind tunnel, simulates the turbine design point of a full-stage turbine. The thesis describes the aerodynamic and mechanical design of the new facility, a rigorous stress analysis of the facility’s rotating system and the three-stage commissioning of the facility. The thesis concludes with an assessment of the turbine stage performance

An examination of leadership development: a role based perspective

Little previous research has examined leadership from a role-based perspective. Those scholars who have studied the subject have focused on the emergence of high-status individuals within a group into complementary leadership roles, with other group members adopting follower roles. In contrast, the current inquiry examines the networked and distributed form of leadership. It is proposed that firstly, executives need to be prepared to adopt "leadership roles” complementary to those of other group members and secondly, that executives need to be prepared to switch leadership roles and membership of groups in order to fulfil their leadership responsibilities. The methodology adopted was qualitative, enabling data to be gathered on aspects of the social structures that executives formed within the formal, informal and temporary groups of which they were a part. The methodology provided insight into the leadership roles available to executives, and between which they switched, as leadership was shared between, and rotated amongst, group members. The inquiry was conducted in six separate, but linked, studies utilising a constructivist ontology and interpretivist epistemology. Characterisation of leadership in terms of role was found to facilitate improvement in the speed with which groups of executives formed around organisational problems, and gained productive contributions from their members. In so doing the inquiry assists executives within a senior management team to better adapt and coordinate their behaviour when mobilising organisational resources. The inquiry was conducted within six organisations, each of which is a multinational engineering company. The concepts advanced will require validating in other organisations of both similar and different demographic profiles. The concepts advanced provide an insight into the distributed form of leadership, and also the nature of leadership as a network of relationships. Leadership is characterised in terms of role, with each executive within a group adopting one of the available leadership roles. All group members contribute towards the tasks of leadership. None are characteristed as adopting purely follower roles

Innovation in industrial turbomachinery

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Destructive behaviours and leadership: the source of the shift from a functional to dysfunctional workplace?

Destructive leadership behaviour often results in damage to the organisations that the individual is entrusted to lead. Although accurately pinpointing the type of destructive behaviour is difficult, this article seeks to offer suggestions as to why leaders spiral into such unattractive behaviour. After reviewing the literature, this paper highlights four drivers for destructive ways that people act based on detailed qualitative scenarios that involve how those who experienced such behaviour reacted and felt. The study reveals a noticeable human experience from which nobody can escape, and offers understanding of the study participants’ experiences. Out of respect to the participants, the authors keep their identity anonomous. We drew our subjects from a cross-section of organisations that function internationally within one area of the manufacturing industry. The article presents a model comprising two dimensions: 1) the leader’s attitude to the organisation he or she leads and 2) adequacy of his or her leadership capabilities. The models offer us understanding of the drivers of the destructive actions that the leader exhibits. Understanding allows us to provide managers with tactical methods to protect them against destructive behaviour and help them lessen the worst aspects of destructive behaviour in both their colleagues and themselves