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Scott B. Lattime

Bio: Scott B. Lattime is an academic researcher from Timken Company. The author has contributed to research in topics: Turbine & Tip clearance. The author has an hindex of 10, co-authored 14 publications receiving 607 citations. Previous affiliations of Scott B. Lattime include University of Akron & Glenn Research Center.

Papers
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Journal ArticleDOI
TL;DR: In this article, the authors present an overview of turbomachinery sealing to control clearances, including characteristics of gas and steam turbine sealing applications and environments, benefits of sealing, types of standard static and dynamics seals, advanced seal designs, as well as life and limitations issues.
Abstract: Clearance control is of paramount importance to turbomachinery designers and is required to meet today's aggressive power output, efficiency, and operational life goals. Excessive clearances lead to losses in cycle efficiency, flow instabilities, and hot gas ingestion into disk cavities. Insufficient clearances limit coolant flows and cause interface rubbing, overheating downstream components and damaging interfaces, thus limiting component life. Designers have put renewed attention on clearance control, as it is often the most cost effective method to enhance system performance. Advanced concepts and proper material selection continue to play important roles in maintaining interface clearances to enable the system to meet design goals. This work presents an overview of turbomachinery sealing to control clearances. Areas covered include: characteristics of gas and steam turbine sealing applications and environments, benefits of sealing, types of standard static and dynamics seals, advanced seal designs, as well as life and limitations issues.

201 citations

01 Sep 2003
TL;DR: In this article, the cause and effect of gas turbine blade tip seal wear and current clearance control practices are reviewed. And the approaches under investigation at GRC are presented, as well as the results of the investigation.
Abstract: This presentation reviews the following: (i) Cause and effect of gas turbine blade tip seal wear (ii) Current clearance control practices (iii) Present approaches under investigation at GRC.

134 citations

Journal ArticleDOI
TL;DR: In this paper, a review of aero-gas-turbine engine high-pressure turbine performance degradation and the mechanisms that promote these losses are presented, along with specifications for next-generation engine clearance control systems.
Abstract: Improved blade-tip sealing in a high-pressure compressor and high-pressure turbine can provide dramatic improvements in specific fuel consumption, time on wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1 million. Removal of engines from service is primarily due to the spent exhaust gas temperature margin caused mainly by the deterioration of high-pressure-turbine components. Increased blade-tip clearance is a major factor in hot-section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero-gas-turbine engine high-pressure-turbine performance degradation and the mechanisms that promote these losses are presented. Benefits to the high-pressure turbine due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next-generation engine clearance control systems.

116 citations

Proceedings ArticleDOI
01 Sep 2002
TL;DR: Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities as mentioned in this paper.
Abstract: Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

71 citations

Journal ArticleDOI
TL;DR: In this article, a first generation mechanically actuated active clearance control system for turbine blade tip clearance management is presented along with the design of a bench top test rig in which the system is to be evaluated.
Abstract: Improved blade tip sealing in the high pressure compressor and high pressure turbine can provide dramatic improvements in specific fuel consumption, time-on-wing, compressor stall margin and engine efficiency as well as increased payload and mission range capabilities of both military and commercial gas turbine engines. The design of a first generation mechanically actuated active clearance control system for turbine blade tip clearance management is presented along with the design of a bench top test rig in which the system is to be evaluated. The active clearance control system utilizes mechanically actuated seal carrier segments and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. The purpose of this active clearance control system is to improve upon current case cooling methods. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, re-burst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). The active turbine blade tip clearance control system design presented herein will be evaluated to ensure that proper response and positional accuracy is achievable under simulated high-pressure turbine conditions. The test rig will simulate proper seal carrier pressure and temperature loading as well as the magnitudes and rates of blade tip clearance changes of an actual gas turbine engine. The results of these evaluations will be presented in future works.

42 citations


Cited by
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Journal ArticleDOI
TL;DR: A review of the interdisciplinary efforts to better understand the design principles for products with honeycomb structures, including their fabrication, performance (e.g., mechanical, thermal and acoustic properties) as well as optimization design is presented in this article.

451 citations

Journal ArticleDOI
TL;DR: In this article, the authors present an overview of turbomachinery sealing to control clearances, including characteristics of gas and steam turbine sealing applications and environments, benefits of sealing, types of standard static and dynamics seals, advanced seal designs, as well as life and limitations issues.
Abstract: Clearance control is of paramount importance to turbomachinery designers and is required to meet today's aggressive power output, efficiency, and operational life goals. Excessive clearances lead to losses in cycle efficiency, flow instabilities, and hot gas ingestion into disk cavities. Insufficient clearances limit coolant flows and cause interface rubbing, overheating downstream components and damaging interfaces, thus limiting component life. Designers have put renewed attention on clearance control, as it is often the most cost effective method to enhance system performance. Advanced concepts and proper material selection continue to play important roles in maintaining interface clearances to enable the system to meet design goals. This work presents an overview of turbomachinery sealing to control clearances. Areas covered include: characteristics of gas and steam turbine sealing applications and environments, benefits of sealing, types of standard static and dynamics seals, advanced seal designs, as well as life and limitations issues.

201 citations

Journal ArticleDOI
TL;DR: An improved method for product architecting using clustering of component-based Design Structure Matrices (DSMs) is presented and demonstrated, covering all relevant aspects from data acquisition, and handling of multiple perspectives in DSM clustering, to a post-processing phase, where results are corrected with respect to technical feasibility.
Abstract: Modular product architectures can offer many benefits, but require carefully chosen interfaces as early as possible in the development process to exploit their full potential. Late or erroneous definition of modules and interfaces results in excessive design iterations and consequently causes unanticipated delays and cost overruns in product development. In this article, an improved method for product architecting (i.e. the identification and definition of modules and their interfaces) using clustering of component-based Design Structure Matrices (DSMs) is presented and demonstrated. Various researchers contributed to the improvement of clustering techniques in the past. However, the approaches used are mostly unsatisfactory with respect to the definition of modules for products resulting in suboptimal or even wrong definitions. In lieu of investigating single steps of DSM clustering, a comprehensive approach is presented in this article, covering all relevant aspects, from data acquisition, and handling ...

113 citations

Journal ArticleDOI
TL;DR: In this article, an extensive review of research efforts on erosion in aviation and a basis for comparison between different apparatus simulating rain erosion and their usage within the aerospace industry is provided. And the significant aspects of erosion testing and future prospects for erosion impact are further addressed for forthcoming generations of flying vehicles.

113 citations

Journal ArticleDOI
TL;DR: In this paper, a dual-rotor system capable of describing the mechanical vibration resulting from two imbalances and fixed point rubbing is established, considering the effects of the softer coatings painted on the discs and casing, the Lankarani-Nikravesh model is applied to describe the impact force between the compressor disc of the low pressure rotor and the casing convex point.

79 citations