The Development of the Whittle Turbojet

1998 ◽  
Vol 120 (2) ◽  
pp. 249-256 ◽  
Author(s):  
C. B. Meher-Homji
Keyword(s):  
Centrifugal Compressor ◽  
Mechanical Engineering ◽  
State Of The Art ◽  
Design Approach ◽  
Technical Aspects ◽  
Governmental Support ◽  
Technical Manpower ◽  
Turbine Design ◽  
Institutional Challenges ◽  
Technology Level

Sir Frank Whittle passed away on August 8, 1996, at the age of 89, in Maryland. His work in developing the turbojet can truly be said to represent one of the greatest mechanical engineering achievements in the last 70 years. The development of the turbojet demanded that Whittle face almost insurmountable technical and institutional challenges. The technical challenges included developing centrifugal compressor pressure ratios of 4:1 from the prevailing technology level of 2.5:1, increasing compressor efficiencies from 65 to 80 percent while designing for combustion intensities that were 10 times the prevailing state of the art in boiler technology. He was also responsible for utilizing a vortex turbine design approach. The institutional challenges that he faced included changing a paradigm on aircraft propulsion technology and nurturing Power Jets Ltd. to produce excellent engine designs with minimal resources in terms of money, technical manpower, and governmental support. It is the object of this paper to document the epic long-drawn-out struggle fought by Sir Frank against entrenched technical opinion, which ultimately resulted in the turbojet revolution. The technical aspects of his pioneering work with emphasis on the problems he encountered will also be discussed.

scholarly journals The Development of the Whittle Turbojet

1997 ◽  
Author(s):  
Cyrus B. Meher-Hornji
Keyword(s):  
Centrifugal Compressor ◽  
Mechanical Engineering ◽  
State Of The Art ◽  
Design Approach ◽  
Technical Aspects ◽  
Governmental Support ◽  
Technical Manpower ◽  
Turbine Design ◽  
Institutional Challenges ◽  
Technology Level

Sir Frank Whittle passed away on August 8, 1996 at the age of 89, in Maryland. His work in developing the turbojet can truly be said to represent one of the greatest mechanical engineering achievements in the last 70 years. The development of the turbojet demanded that Whittle face almost insurmountable technical and institutional challenges. The technical challenges included developing centrifugal compressor pressure ratios of 4:1 from the prevailing technology level of 2.5:1, increasing compressor efficiencies from 65 to 80% while designing for combustion intensities that were 10 times the prevailing state of the art in boiler technology. He was also responsible for utilizing a vortex turbine design approach. The institutional challenges that he faced included changing a paradigm on aircraft propulsion technology and nurturing Power Jets Ltd. to produce excellent engine designs with minimal resources in terms of money, technical manpower and governmental support. It is the object of this paper to document the epic long drawn out struggle fought by Sir Frank against entrenched technical opinion that ultimately resulted in the turbojet revolution. The technical aspects of his pioneering work with emphasis on the problems he encountered will also be discussed.

Centralizing Integrated Long Range Planning and Budgeting

2011 ◽  
pp. 55-75
Author(s):  
Taylor Valore
Keyword(s):  
Long Range ◽  
State Of The Art ◽  
Technical Aspects ◽  
American University ◽  
Independent Events ◽  
Long Range Planning ◽  
American University In Cairo ◽  
Annual Planning

Upon relocation to a new, state-of-the-art, 260-acre campus outside of Cairo, Egypt, the American University in Cairo (AUC) sought to revamp its annual planning and budgeting processes to address several deficiencies. Primarily, long-range planning and annual budgeting were two independent events with little synchronization. This case study will detail the process and technical aspects of AUC’s transition to a centralized and synchronized planning and budgeting cycle focused on determining appropriate workflows and leveraging database technologies to track planning initiatives throughout an approvals process. Readers will be able to weigh the drawbacks of centralization against the benefits of standardized budget review and planning.

On the Influence of a Hubside Exducer Cavity and Bleed Air in a Close-Coupled Centrifugal Compressor Stage

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Peter Kaluza ◽  
Christian Landgraf ◽  
Philipp Schwarz ◽  
Peter Jeschke ◽  
Caitlin Smythe
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Field ◽  
State Of The Art ◽  
Test Rig ◽  
Cfd Simulations ◽  
Trailing Edge ◽  
Loss Mechanism ◽  
Aero Engine ◽  
Computational Fluid Dynamics Cfd ◽  
Stage Efficiency

In aero-engine applications, centrifugal compressors are often close-coupled with their respective diffusers to increase efficiency at the expense of a reduced operating range. The aim of this paper is to show that state-of-the art steady-state computational fluid dynamics (CFD) simulations can model a hubside cavity between an impeller and a close-coupled diffuser and to enhance the understanding of how the cavity affects performance. The investigated cavity is located at the impeller trailing edge, and bleed air is extracted through it. Due to geometrical limitations, the mixing plane is located in the cavity region. Therefore, the previous analyses used only a cut (“simple”) model of the cavity. With the new, “full” cavity model, the region inside the cavity right after the impeller trailing edge is not neglected anymore. The numerical setup is validated using the experimental data gathered on a state-of-the art centrifugal compressor test-rig. For the total pressure field in front of the diffuser throat, a clear improvement is achieved. The results presented reveal a drop in stage efficiency by 0.5%-points caused by a new loss mechanism at the impeller trailing edge. On the hubside, the fundamentally different interaction of the cavity with the coreflow increases the losses in the downstream components resulting in the mentioned stage efficiency drop. Finally, varying bleed air extraction is investigated with both cavity models. Only the full cavity (FC) model captures the changes measured in the experiment.

Evolution of Gas Turbines Auxiliary Systems Designed for Reliability

1993 ◽  
Author(s):  
Jacek Misiowiec ◽  
Tim McElwee ◽  
Sal DellaVilla
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Operational Reliability ◽  
Design Approach ◽  
Design For Reliability ◽  
Design Evolution ◽  
Low Nox Combustion ◽  
Design Characteristics ◽  
Turbine Design

Gas turbine design evolution and practice is driven by industry demand for increased output and improved operating efficiencies. New aerothermal design characteristics require a focus on improved materials and coatings, and cooling techniques. As environmental issues continue to confront the industry, Dry Low NOx combustion system designs represent a significant opportunity for meeting new emissions requirements. These issues represent opportunity for significant technology improvements and industry driven advances. However, just as important is the design evolution of the Control and Auxiliary systems which support the gas turbine. Historically, these support systems, as demonstrated by the Operational Reliability Analysis Program (ORAP), are typically the primary drivers of plant Availability and Reliability. Following a rigorous “Design for Reliability” approach provides opportunities for ensuring that the design meets three critical requirements: starting reliability, a minimum of unit shutdowns during operating demand periods and ease of maintenance. The design approach for the Control and Auxiliary systems for new turbine design (product improvement) therefore provides an opportunity for developing a uniform and standardized approach which continues to focus on Reliability, Availability, and Maintainability. This design approach also provides opportunities for improved field installation and reduced cycle time, a major benefit for the end user. This paper will describe the “Design for Reliability” approach followed by ABB Power Generation, Inc., and supported by Strategic Power Systems, Inc.® (SPS) for the GT11N2 auxiliary systems. The extension of the ORAP system for auxiliary systems will be discussed as the approach for monitoring unit Availability and Reliability, maintaining configuration control, and for promoting continuous improvement.

The Influence of Physical Examples on Originality and Fixation in Engineering Design

2018 ◽  
Author(s):  
Christopher C. Simmons ◽  
Trina C. Kershaw ◽  
Alexander LeGendre ◽  
Sankha Bhowmick
Keyword(s):  
Engineering Design ◽  
Significant Relationship ◽  
Mechanical Engineering ◽  
Engineering Students ◽  
Garbage Collection ◽  
Negative Relationship ◽  
Design Approach ◽  
Engineering Program ◽  
The Relationship

Improving creativity in engineering design continues to be a challenge. The relationship between fixation and creativity within engineering is mixed, as engineers desire to be innovative, yet are usually working from their existing knowledge to redesign existing products. In the current study, we wanted to examine the influence of physical examples on originality and fixation at the freshmen and senior level in a Mechanical Engineering program. We compared concepts for garbage collection systems generated by two groups — one provided with an example product (Example group), and another who did not receive an example product (No Example group). Using metrics established in prior publications, we found that seniors had higher levels of originality than freshmen whether an example product was received or not, reinforcing our previous findings. Fixation scores were higher for the group that did have an example. Receiving an example product was not a predictor of originality on its own, but did interact with curriculum and fixation level. Within the group that received an example product, there was a negative relationship between fixation and originality, particularly for the seniors. Within the group that did not receive an example product, there was no significant relationship between fixation and originality. Further analysis of our results are required to delineate how not receiving an example product influences design approach in freshmen and senior engineering students.

A Review of In-Place Design Approaches for Spar Hulls

2005 ◽  
Author(s):  
Cheng-Yo Chen ◽  
Trevor Mills
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Current Practice ◽  
State Of The Art ◽  
Element Model ◽  
Maximum Strength ◽  
Design Approach ◽  
Structural Components ◽  
Advantages And Disadvantages ◽  
Design Loads

This paper reviews the current practice for the in-place design of Spar hulls. Both the commonly-used approach and the state-of-the-art procedure for the maximum strength and fatigue conditions will be presented. Key assumptions for various design approaches will be discussed along with advantages and disadvantages of each approach. The review will focus on how each approach generates hydrodynamic loadings, performs global motions analysis, and maps design loads from motion analyses to structural finite-element model. Important aspects relating to Spar design will be addressed. In particular, effect of vortex induced hull motions (VIM) will be discussed, and an approach for including the VIM effect in the design of moorings and risers will also be described. Impact on the maximum strength and fatigue capacity of critical structural components due to the assumptions employed in the commonly-used design approach will be evaluated and quantified as compared to the results from the more rigorous state-of-the-art approach.

An introduction to “Computational Crystallography”

1999 ◽  
Vol 214 (9) ◽  
Author(s):  
B. Winkler
Keyword(s):  
State Of The Art ◽  
The State ◽  
Technical Aspects ◽  
Future Developments

AbstractThe currently available methods for the computation of structures and their properties are reviewed. After a brief introduction into some common technical aspects, the capabilities and limitations of the most commonly used approaches are discussed. Examples are given to show the state of the art in Computational “Crystallography”, and possible future developments are outlined

LITERATURE REVIEW ON LINACs AND FFAGs FOR HADRON THERAPY

2011 ◽  
Vol 26 (10n11) ◽  
pp. 1659-1689 ◽  
Author(s):  
SILVIA VERDÚ-ANDRÉS ◽  
UGO AMALDI ◽  
ÁNGELES FAUS-GOLFE
Keyword(s):  
Literature Review ◽  
Radio Frequency ◽  
State Of The Art ◽  
Public Information ◽  
Linear Accelerators ◽  
Middle Term ◽  
Technical Aspects ◽  
Fixed Field ◽  
General Overview ◽  
Hadron Therapy

The document summarizes the recent papers, presentations and other public information on Radio-Frequency (RF) Linear Accelerators (linacs) and Fixed-Field Alternating-Gradient (FFAG) accelerators for hadron therapy. The main focus is on technical aspects of these accelerators. This report intends to provide a general overview of the state-of-the-art in those accelerators which could be used in short and middle-term for treating cancer.

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