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All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Mapping of Technological Opportunities-Labyrinth Seal Example

All technological systems evolve based on evolutionary sequences that have repeated throughout history and can be abstracted from the history of technology and patents. These evolutionary sequences represent objective patterns and provide considerable insights that can be used to proactively model future seal concepts. This presentation provides an overview of how to map seal technology into the future using a labyrinth seal example. The mapping process delivers functional descriptions of sequential changes in market/consumer demand, from today s current paradigm to the next major paradigm shift. The future paradigm is developed according to a simple formula: the future paradigm is free of all flaws associated with the current paradigm; it is as far into the future as we can see. Although revolutionary, the vision of the future paradigm is typically not immediately or completely realizable nor is it normally seen as practical. There are several reasons that prevent immediate and complete practical application, such as: 1) Some of the required technological or business resources and knowledge not being available; 2) Availability of other technological or business resources are limited; and/or 3) Some necessary knowledge has not been completely developed. These factors tend to drive the Total Cost of Ownership or Utilization out of an acceptable range and revealing the reasons for the high Total Cost of Ownership or Utilization which provides a clear understanding of research opportunities essential for future developments and defines the current limits of the immediately achievable improvements. The typical roots of high Total Cost of Ownership or Utilization lie in the limited availability or even the absence of essential resources and knowledge necessary for its realization. In order to overcome this obstacle, step-by-step modification of the current paradigm is pursued to evolve from the current situation toward the ideal future, i.e., evolution rather than revolution. A key point is that evolutionary stages are mapped to show step-by-step evolution from the current paradigm to the next major paradigm.

Clarke, Dana W., Sr.↗
DOE OSTI2015

Field Test and Evaluation of Engineered Biomineralization Technology for Sealing Existing Wells

This research project addresses one of the goals of the U.S. Department of Energy (DOE) Carbon Storage Program (CSP) aimed at developing Advanced Wellbore Integrity Technologies to Ensure Permanent Geologic Carbon Storage. The technology field-tested in this research project is referred to as microbially induced calcite precipitation (MICP), which utilizes a biologically-based process to precipitate calcium carbonate. If properly controlled MICP can successfully seal fractures, high permeability zones, and compromised wellbore cement in the vicinity of wellbores and in nearby caprock, thereby improving the storage security of geologically-stored carbon dioxide. This report describes an MICP sealing field test performed on a 24.4 cm (9.625 inch) diameter well located on the Gorgas Steam Generation facility near Jasper, Alabama. The research was aimed at (1) developing methods for delivering MICP promoting fluids downhole using conventional oil field technologies and (2) assessing the ability of MICP to seal cement and formation fractures in the near wellbore region in a sandstone formation. Both objectives were accomplished successfully during a field test performed during the period April 1-11, 2014. The test resulted in complete biomineralization sealing of a horizontal fracture located 340.7 m (1118 feet) below ground surface. A total of 24 calcium injections and six microbial inoculation injections were required over a three day period in order to achieve complete sealing. The fractured region was considered completely sealed when it was no longer possible to inject fluids into the formation without exceeding the initial formation fracture pressure. The test was accomplished using conventional oil field technology including an 11.4 L (3.0 gallon) wireline dump bailer for injecting the biomineralization materials downhole. Metrics indicating successful MICP sealing included reduced injectivity during seal formation, reduction in pressure falloff, and demonstration of MICP by-products including calcium carbonate (CaCO 3 ) in treated regions of side wall cores. This project successfully integrated mesoscale laboratory experiments at the Center for Biofilm Engineering (CBE) together with simulation modeling conducted at the University of Stuttgart to develop the protocol for conducting the biomineralization sealing test in the field well.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2000

1999 NASA Seal/secondary Air System Workshop

NASA Glenn hosted the Seals/Secondary Air System Workshop on October 28-29, 1999. Each year NASA and our industry and university partners share their respective seal technology development. We use these workshops as a technical forum to exchange recent advancements and "lessons-leamed" in advancing seal technology and solving problems of common interest. As in the past we are publishing two volumes. Volume 1 will be publicly available and volume 2 will be restricted under International Traffic and Arms Regulations (I.T.A.R.). The 1999 NASA Seal/Secondary Air System Workshop was divided into four areas; (i) overviews of the government-sponsored gas turbine programs (NASA Ultra Efficient Engine Technology program and DOE Advanced Turbine System program) and the general aviation program (GAP) with emphasis on program goals and seal needs; (ii) turbine engine seal issues from the perspective of an airline customer (i.e., United Airlines), (iii) sealing concepts, methods and results including experimental facilities and numerical predictions; and (iv) reviews of seal requirements for next generation aerospace vehicles (Trailblazer, Bantam and X-38).

Steinetz, Bruce M.↗
NASA NTRS2000

1999 NASA Seal/Secondary Air System Workshop

NASA Glenn hosted the Seals/Secondary Air System Workshop on October 2829, 1999. Each year NASA and our industry and university partners share their respective seal technology development. We use these workshops as a technical forum to exchange recent advancements and "lessons-learned" in advancing seal technology and solving problems of common interest. As in the past we are publishing two volumes. Volume 1 will be publicly available and will be made available on-line through the web page address listed at the end of this chapter. Volume 2 will be restricted under International Traffic and Arms Regulations (I.T.A.R.) In this conference participants gained an appreciation of NASA's new Ultra Efficient Engine Technology (UEET) program and how this program will be partnering with ongoing DOE -industrial power production and DOD- military aircraft engine programs. In addition to gaining a deeper understanding into sealing advancements and challenges that lie ahead, participants gained new working and personal relationships with the attendees. When the seals and secondary fluid management program was initiated, the emphasis was on rocket engines with spinoffs to gas turbines. Today, the opposite is true and we are, again building our involvement in the rocket engine and space vehicle demonstration programs.

Steinetz, Bruce M.↗
NASA NTRS2001

Overview of NASA Glenn Seal Development Program

NASA Glenn hosted the Seals/Secondary Air System Workshop on October 25-26, 2000. Each year NASA and our industry and university partners share their respective seal technology developments. We use these workshops as a technical forum to exchange recent advancements and 'lessons-learned' in advancing seal technology and solving problems of common interest. As in the past we are publishing two volumes. Volume I will be publicly available and individual papers will be made available online through the web page address listed at the end of this chapter.

Steinetz, Bruce M.↗
NASA NTRS2002

Overview of NASA Glenn Seal Program

NASA Glenn hosted the Seals/Secondary Air System Workshop on October 30-31, 2001. Each year NASA and our industry and university partners share their respective seal technology developments. We use these workshops as a technical forum to exchange recent advancements and "lessons-learned" in advancing seal technology and solving problems of common interest. As in the past we are publishing two volumes. Volume I will be publicly available and individual papers will be made available on-line through the web page address listed at the end of this chapter. Volume II will be restricted under International Traffic and Arms Regulations (I.T.A.R.) and/or Export Administration Regulations (E.A.R.).

Steinetz, Bruce M.↗
NASA NTRS2007

Overview of NASA Glenn Seal Project

NASA Glenn hosted the Seals/Secondary Air System Workshop on November 14-15, 2006. At this workshop NASA and our industry and university partners shared their respective seal technology developments. We use these workshops as a technical forum to exchange recent advancements and "lessons-learned" in advancing seal technology and solving problems of common interest. As in the past we are publishing the presentations from this workshop in two volumes. Volume I will be publicly available and individual papers will be made available on-line through the web page address listed at the end of this presentation. Volume II will be restricted as Sensitive But Unclassified (SBU) under International Traffic and Arms Regulations (ITAR).

Steinetz, Bruce M.↗
NASA NTRS1996

Air Force Seal Programs

Seal technology development is an important part of the Air Force's participation in the Integrated High Performance Turbine Engine Technology (IHPTET) initiative, the joint DOD, NASA, ARPA, and industry endeavor to double turbine engine capabilities by the turn of the century. Significant performance and efficiency improvements can be obtained through reducing internal flow system leakage, but seal environment requirements continue to become more extreme as the engine thermodynamic cycles advance towards these IHPTET goals. Seal technology continues to be pursued by the Air Force to control leakage at the required conditions. This presentation briefly describes current seal research and development programs and gives a summary of seal applications in demonstrator and developmental engines.

Mayhew, Ellen R.↗
NASA NTRS1994

Air Force seal activities

Seal technology development is an important part of the Air Force's participation in the Integrated High Performance Turbine Engine Technology (IHPTET) initiative, the joint DOD, NASA, ARPA, and industry endeavor to double turbine engine capabilities by the turn of the century. Significant performance and efficiency improvements can be obtained through reducing internal flow system leakage, but seal environment requirements continue to become more extreme as the engine thermodynamic cycles advance towards these IHPTET goals. Brush seal technology continues to be pursued by the Air Force to reduce leakage at the required conditions. Likewise, challenges in engine mainshaft air/oil seals are also being addressed. Counter-rotating intershaft applications within the IHPTET initiative involve very high rubbing velocities. This viewgraph presentation briefly describes past and current seal research and development programs and gives a summary of seal applications in demonstrator and developmental engine testing.

Mayhew, Ellen R.↗
NASA NTRS2005

Adaptive Development

The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

Source record↗
NASA NTRS2003

Advanced Control Surface Seal Development at NASA GRC for Future Space Launch Vehicles

NASA s Glenn Research Center (GRC) is developing advanced control surface seal technologies for future space launch vehicles as part of the Next Generation Launch Technology project (NGLT). New resilient seal designs are currently being fabricated and high temperature seal preloading devices are being developed as a means of improving seal resiliency. GRC has designed several new test rigs to simulate the temperatures, pressures, and scrubbing conditions that seals would have to endure during service. A hot compression test rig and hot scrub test rig have been developed to perform tests at temperatures up to 3000 F. Another new test rig allows simultaneous seal flow and scrub tests at room temperature to evaluate changes in seal performance with scrubbing. These test rigs will be used to evaluate the new seal designs. The group is also performing tests on advanced TPS seal concepts for Boeing using these new test facilities.

Dunlap, Patrick H., Jr.↗
NASA NTRS1997

Habitats and Surface Construction Technology and Development Roadmap

The vision of the technology and development teams at NASA Ames and Johnson Research Centers is to provide the capability for automated delivery and emplacement of habitats and surface facilities. The benefits of the program are as follows: Composites and Inflatables: 30-50% (goal) lighter than Al Hard Structures; Capability for Increased Habitable Volume, Launch Efficiency; Long Term Growth Potential; and Supports initiation of commercial and industrial expansion. Key Habitats and Surface Construction (H&SC) technology issues are: Habitat Shell Structural Materials; Seals and Mechanisms; Construction and Assembly: Automated Pro-Deploy Construction Systems; ISRU Soil/Construction Equipment: Lightweight and Lower Power Needs; Radiation Protection (Health and Human Performance Tech.); Life Support System (Regenerative Life Support System Tech.); Human Physiology of Long Duration Space Flight (Health and Human Performance Tech.); and Human Psychology of Long Duration Space Flight (Health and Human Performance Tech.) What is being done regarding these issues?: Use of composite materials for X-38 CRV, RLV, etc.; TransHAB inflatable habitat design/development; Japanese corporations working on ISRU-derived construction processes. What needs to be done for the 2004 Go Decision?: Characterize Mars Environmental Conditions: Civil Engineering, Material Durability, etc.; Determine Credibility of Inflatable Structures for Human Habitation; and Determine Seal Technology for Mechanisms and Hatches, Life Cycle, and Durability. An overview encompassing all of the issues above is presented.

Marc Cohen↗
NASA NTRS2006

Advanced Docking Berthing System Update

In FY05 the Exploration Systems Technology Maturation Program selected the JSC advanced mating systems development to continue as an in-house project. In FY06, as a result of ESAS Study (60 Day Study) the CEV Project (within the Constellation Program) has chosen to continue the project as a GFE Flight Hardware development effort. New requirement for CEV to travel and dock with the ISS in 2011/12 in support of retiring the Shuttle and reducing the gap of time where US does not have any US based crew launch capability. As before, long-duration compatible seal-on-seal technology (seal-on-seal to support androgynous interface) has been identified as a risk mitigation item.

Lewis, James↗
NASA NTRS1994

Brush seal numerical simulation: Concepts and advances

The development of the brush seal is considered to be most promising among the advanced type seals that are presently in use in the high speed turbomachinery. The brush is usually mounted on the stationary portions of the engine and has direct contact with the rotating element, in the process of limiting the 'unwanted' leakage flows between stages, or various engine cavities. This type of sealing technology is providing high (in comparison with conventional seals) pressure drops due mainly to the high packing density (around 100 bristles/sq mm), and brush compliance with the rotor motions. In the design of modern aerospace turbomachinery leakage flows between the stages must be minimal, thus contributing to the higher efficiency of the engine. Use of the brush seal instead of the labyrinth seal reduces the leakage flow by one order of magnitude. Brush seals also have been found to enhance dynamic performance, cost less, and are lighter than labyrinth seals. Even though industrial brush seals have been successfully developed through extensive experimentation, there is no comprehensive numerical methodology for the design or prediction of their performance. The existing analytical/numerical approaches are based on bulk flow models and do not allow the investigation of the effects of brush morphology (bristle arrangement), or brushes arrangement (number of brushes, spacing between them), on the pressure drops and flow leakage. An increase in the brush seal efficiency is clearly a complex problem that is closely related to the brush geometry and arrangement, and can be solved most likely only by means of a numerically distributed model.

Braun, M. J.↗
NASA NTRS1994

Hypersonic engine seal development at NASA Lewis Research Center

NASA Lewis Research Center is developing advanced seal concepts and sealing technology for advanced combined cycle ramjet/scramjet engines being designed for the National Aerospace Plane (NASP). Technologies are being developed for both the dynamic seals that seal the sliding interfaces between articulating engine panels and sidewalls, and for the static seals that seal the heat exchanger to back-up structure interfaces. This viewgraph presentation provides an overview of the candidate engine seal concepts, seal material assessments, and unique test facilities used to assess the leakage and thermal performance of the seal concepts.

Steinetz, Bruce M.↗
NASA NTRS2004

Leakage and Power Loss Test Results for Competing Turbine Engine Seals

Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufacturers concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s).

Proctor, Margaret P.↗
NASA NTRS1991

Seal development activities at Allison Turbine Division

Brush seals are being evaluated for potential near and far term gas turbine engine applications. Development is in the form of rig component testing and engine testing. Allison has tested an engine with 20 individual brush seal positions. These seals were located throughout the engine. The emphasis of the current work is on obtaining long term performance data for brush seals. Very little of this data is available. Allison is presently developing film riding face seal technology to support future gas turbine engine applications. A face seal with an approximate 7 inch diameter was successfully tested to 1000 F, 100 psid, and 650 ft/sec. Seal leakage remained below 1 scfm throughout the duration of the test. A model for the compressible gas film was developed which separates the model for the compressible gas film was developed which separates the primary seal rings during operation. This model is based on the traditional Reynold's approach which is customarily applied to lubrication type problems. Because of the difficulty of experimentally verifying the program predictions, a commercial Navier-Stokes code was used in parallel. By comparing predictions for similar cases, it is expected that the limitations of the Reynold's model can be assessed as it applies to this particular seal.

Munson, John↗