AIAA GTTC HANDBOOK
SECTION VII – WORKING GROUPS (This page is under construction)
Working Group
Quick Finder
|
|
|
|
|
|
Working
Group Summary Presentations from the Portland, OR - GT Conference 2004 :
Click Here (2.4MB Zip file, MS Powerpoint
2002 Format)
Working Groups were developed
under the GTTC in order to address specific technical issues of interest to the
ground testing community. The idea
for a specific Working Group comes from either inside the GTTC or from
recommendations outside the GTTC.
For any Working Group to be formed, a GTTC member must become its
champion and chair. The Working
Group must develop a charter (similar to a Task Subcommittee Charter) that
details its operation and objectives. A Working Group differs from a Task Subcommittee in that:
- A Working Group is allowed and encouraged to have
members from outside the GTTC ranks.
This is necessary to insure that the proper amount of expert
staffing is available to address the specific topic of the Working Group.
- A Working Group has a finite lifespan. The Working Group charter will
address the specific goals and deliverables of the Working Group. Once these goals are met and the
deliverables completed, the Working Group will disband, or must re-charter
itself to address new technical issues (with approval of the GTTC).
Timeline for GTTC Working Group
Operation: As mentioned above, a
GTTC Working Group is chaired and championed by a GTTC member (although
non-GTTC members can be involved in championing a new Working Group, as
well). The process and approximate
timeline for establishing and operating a Working Group is described below:
- The Working Group
champion will inform the GTTC Steering Committee of plans on the formation
of a new working group. During the formation period, the draft charter
with the Working Group objectives will be created, and the initial Working
Group membership list will be developed.
- The proposed Working
Group will be allowed to meet under the operating umbrella of the GTTC for
up to two meetings (e.g. a proposed Working Group could hold an initial
kick-off meeting in conjunction with a GTTC winter meeting then if needed
hold a second organizational meeting at the next summer GTTC meeting
site).
- The kick-off
meeting(s) will be primarily used by the proposed Working Group to
finalize the charter and objectives, select Working Group officers, and
develop an overall plan and schedule for the Working Group.
·
As noted, the Working Group Chair must be a GTTC
member. Other Working Group
officers (vice-chair, secretary) are not required to be GTTC members.
- Once the Working Group
membership has finalized the charter and overall plans, the Working Group
Chair will present this information to the GTTC membership at the GTTC
general meeting. The GTTC
membership will then vote to formally adopt or reject, the proposed
Working Group.
·
If, following the organization and setup of a proposed
Working Group, the GTTC membership feels that a proposed Working Group has merit,
but has not provided an adequate charter or plan, the GTTC can reject the
proposed Working Group or allow the proposed Working Group one additional
planning meeting to revise the charter and plan.
- Once approved by the
GTTC membership, the Working Group is placed on “active” status. During this period the Working
Group will hold regular meetings (concurrent with the GTTC meetings). This is the period when the Working
Group is actively working toward completing the objectives stated in its
charter (i.e. developing AIAA standards documents).
·
The active period for a Working Group may last 5 years
or longer, depending on the scope of the Working Group objectives.
·
If the primary goal of the Working Group is the
development of an AIAA Standards document, then some coordination/communication
with the GTTC Standards Subcommittee is warranted to insure that proper document review and approval
procedures are followed.
- The Working Group
Chair will provide a report at each GTTC general meeting. The Working Group Chair (or
secretary) will also provide minutes of each Working Group meeting to the
GTTC secretary for inclusion in the GTTC meeting minutes package. Minutes are requested from the
kick-off meeting(s).
- At some point in the
lifespan of a Working Group, it will no longer be necessary for the entire
Working Group membership to meet on a regular basis; however, there are
still tasks that must be completed.
At this point, the Working Group is placed on “inactive” status.
·
If a Working Group is developing an AIAA standards
document, the Working Group will usually switch to inactive status after the
draft standards document has been reviewed by a peer review team, the comments
of that review have been incorporated back into the draft document, and the
document has been approved by the GTTC membership.
·
During the inactive phase, the Working Group chair (or
designee) will act as the point-of-contact with AIAA while AIAA reviews and
publishes the document.
·
A Working Group will remain on inactive status until
the final document is published by AIAA.
·
If necessary, the Working Group can hold occasional
meetings while on inactive status.
- A Working Group that
has completed its primary objectives will not necessarily be disbanded or
simply jettisoned from the GTTC.
Since most Working Groups are developing AIAA standard documents,
it will be necessary to call on the working group membership periodically
to review and update the documents, as directed by the GTTC Standards
Subcommittee (one an AIAA standards document has been published, the
responsibility of maintaining the Working Group-produced document will
shift to the Standards Subcommittee). Once AIAA has published the document
produced by the Working Group, the Working Group is considered to be on
“casual” or as-needed status.
This will allow the GTTC Chair and GTTC Standards Committee Chair
to call on the Working Group membership to aid in the periodic review of
their document. The
responsibility of maintaining the WG-produced document will shift to the
Standards SC.
·
The Working Group chair, though now not a GTTC member,
will be the point-of-contact with the GTTC.
·
A Working Group will remain on casual status as long as
any standard document produced by that Working Group is being maintained by the
AIAA.
- A Working Group can be
recalled to active status as needed to address concerns or requirements of
the GTTC, AIAA or the ground testing community. Recalling a Working Group will require that the Working
Group charter be updated as needed based on the current objectives. New membership and officers will
also be required, as the original members and officers may not be
available.
The GTTC has had great success
through its Working Groups, and for the benefit of future Working Groups, the
GTTC has developed a list of lessons learned in
the formation and operation of Working Groups:
The following is a summary of the
GTTC Working Groups:
·
Current Working Groups:
§
Chair: Frank Steinle (Sverdrup Technology/AEDC)
o
Thrust Stands
§
Chair: Ray Castner (NASA Glenn)
·
Working Groups under construction:
o
Test Nomenclature
§
Champion:
Jerry Kegelman (NASA Langley)
o
Dynamic Testing
§
Champion:
Greg Addingtion (AFRL)
·
Working Groups that have completed their assigned
tasks:
o
Internal
Balances Technology
§
Chair:
David Cahill (Sverdrup Technology / AEDC)
§
Final Product:
AIAA Recommended Practice document AIAA R-091-2003
Calibration and
Use of Internal Strain-Gage Balances
AIAA R-091-2002, 6x96 Matrix Computation
Example
§
Chair:
Mark Melanson (Lockheed Martin)
§
Final Product:
Two-Volume AIAA Recommended Practice document AIAA R-092-2003
Recommended
Practice for Successful Wind Tunnel Testing
Vol. I. Management Guide
Vol. II.
Practitioners Volume
o
Wind Tunnel Calibration Methodology
§
Chair:
Allen Arrington (QSS Group, Inc. / NASA Glenn)
§
Final Product:
AIAA Recommended Practice document AIAA R-093-2003
Calibration of
Subsonic and Transonic Wind Tunnels
AEROSPACE TEST PROCESSES
WORKING GROUP
SCOPE
The Aerospace Test Processes Working Group is assembled to document best
practices associated with wind tunnel testing as a way to recommend improvements
in wind tunnel test efficiency, costs, and cycle time. It is the resolve of the
Test Processes membership to discuss and document, in published form, proven
practices/lessons learned that has contributed to the success of the collective
memberships organizations.
STRUCTURE
Members of the GTTC staff the Aerospace Test Processes Working Group as well
as representatives from wind tunnel model suppliers, users, and test facilities
personnel.
OBJECTIVES
- Identify best practices utilized to improve wind
tunnel test processes.
- Evaluate the R&D function and improved
processes that can enhance future wind tunnel test efforts.
- Survey the wind tunnel research community to
broaden input regarding what works and what doesn't.
- Investigate test methodology with an aim at
reducing cycle or turnaround time.
- Evaluate the R&D function and improved
processes that can enhance future wind tunnel test efforts
- Develop management and technical guidelines for
achieving affordable test programs.
- Select a suitable means for publishing the
results of this Working Group (i.e. AIAA Recommended Practices) and
identify the distribution of these results to the ground testing
community.
OPERATION
- Meet two times annually at times and locations
concurrent with the scheduled
GTTC meetings. - Present a formal report at each GTTC meeting.
- Accept responsibility for organizing and hosting
sessions germane to the scope of GTTC in the technical programs of both
the biennial AIAA Advanced Measurements and Ground Testing Conference and
the annual AIAA Aerospace Sciences meeting.
- Develop a reference source on wind tunnel
testing containing guidelines, recommended practices, and examples of
success and failures from past experiences.
- Actively support, maintain formal and informal
(as appropriate) liaisons, and report on the activities of groups,
agencies, organizations and the like which are involved with wind tunnel
model design and fabrication.
INTERNAL BALANCE AND CALIBRATION TECHNOLOGY
WORKING GROUP
SCOPE
Internal strain-gage balances are used extensively to measure the aerodynamic
loads on a test article during a wind tunnel test. There has been little collaboration
among the users of internal balances and, as a result, several types of
balances, calibration methods, calibration matrices, tare adjustment, and
uncertainty evaluations have evolved. The time has arrived where a
collaborative effort is needed to advance the state-of-the-art for internal
strain-gage balances and calibration technology. Individuals from wind tunnel
facilities will pool their information and experiences to enhance each others
capabilities and to develop standards for their use, calibration, tare
adjustment, and uncertainty evaluation. The working group is not an opportunity
for an organization to promote their particular balance design, fabrication,
and/or calibration services.
STRUCTURE
The Internal Balance and Calibration Technology Working Group was formed under
the auspices of the AIAA Ground Testing Technical Committee (GTTC). The working
group is staffed by selected volunteers from various wind tunnel facilities and
is not limited to members of the GTTC or AIAA. The Chairperson for the working
group shall be a member of the GTTC and will be appointed by the GTTC
Chairperson. An individual's service on the working group will continue until
the objectives for which they were selected have been completed. Currently,
membership on the working group is limited to individuals from facilities
operated by government or commercial enterprises in the US and Canada.
OBJECTIVES
- Provide a forum for the members to learn the
methodologies and capabilities of the various wind tunnel facilities. A
document will be prepared containing a chapter for each facility.
- Develop a calibration matrix (or matrices) which
provides the accuracy required for the type of testing and balance. The
members will agree to be able to use the matrix (matrices) in their test
facilities.
- Determine guidelines for selecting a balance
type that is best suited to meet the objectives of a particular wind
tunnel test.
- Determine the calibration methodology that will
provide the calibration matrix that will meet the objectives of a
particular wind tunnel test.
- Develop a balance calibration uncertainty
methodology that is in agreement with existing uncertainty standards
(AGARD AR-301 and AIAA S-071).
- Develop methods of accounting for tare
adjustments (both calibration and testing) that can be agreed upon by the
members.
- Investigate new methodologies for the design,
attachment, and calibration of internal balances.
- Provide a forum which can be used to solve
balance or calibration problems and to obtain input on new ideas
concerning internal balances and their calibration.
OPERATION
- The working group will meet twice at the times
and locations concurrent with the scheduled GTTC meetings.
- Present a formal report on the status on the
working group at each GTTC meeting.
- Accept responsibility for organizing and hosting
sessions germane to the scope of the working group as requested by the
GTTC.
WIND TUNNEL CALIBRATION WORKING GROUP
SCOPE
Wind tunnels provide a primary source of test data
for basic aerodynamic research and for the design and development of aircraft,
aircraft components and propulsion systems. Due to advances in instrumentation
and data systems that allow for more accurate measurement of the flow
parameters and the increased sensitivity of aerodynamic and propulsion system
performance with wind tunnel flow quality, the accurate calibration of wind
tunnels has become very important. In the past, there have been workshops and
general meetings to discuss issues pertaining to wind tunnel calibration, but
in general, there was no closure or final recommendations produced from these
exercises. The members of the working group will pool their information and
experiences to enhance each others capability in wind tunnel calibration and to
develop standards for tunnel calibration, documentation and presentation of
calibration results and uncertainty analysis.
Due to the large number of variables involved in
wind tunnel testing (Mach number range, size/type of facility, types of
testing, model blockage effects, etc.) it would not be possible to address all
pertinent issues at one time, so the scope of the working group will be focused
on a subset of wind tunnels and test ranges. From discussions with wind tunnel
users/operators from within the GTTC, it was suggested to limit the initial
scope of the working group to subsonic and transonic wind tunnel facilities and
to look only at the aerodynamic calibration of the empty test section of these
types of facilities. The scope of the working group would be changed to cover
other calibration issues (supersonic tunnels, model effects, etc.) as the
initial topics were completed.
STRUCTURE
The Wind Tunnel Calibration Methodology Working
Group was formed under the operating structure of the AIAA Ground testing
Technical Committee (GTTC). The working group will be staffed by
representatives from several wind tunnel facilities and is not limited to
members of the AIAA or GTTC. The Chairperson of the working group shall be a
member of the GTTC and will be appointed by the GTTC Chairperson.
OBJECTIVES
- Provide a forum for the members to share
information on wind tunnel calibration methodologies. A document, which
will remian internal to the working group, will be prepared containing
the calibration details for each subject facility.
- Develop a recommended practice for the
documentation and presentation of wind tunnel calibration data in a
common format to aid in the comparison of test data from different
facilities.
- Develop a recommended practice for quoting
measurement uncertainty that is in agreement with existing uncertainty
standards (AGARD AR-304, AIAA S-071-1995).
- Establich guidelines to aid the development and
scheduling of a wind tunnel calibration program. Items to be adressed
include; definition of the minimum requirements for an empty test section
calibration; flow-field parameters to be measured; instrumentation
options; frequency of and causes for recalibration of a facility.
- Develop and publish a Recommended Practices
document (or documents) for wind tunnel calibration methodologies.
OPERATION
- The working group will meet twice a year at the
times and locations concurrent with the scheduled GTTC meetings.
- A formal report on the status of the working
group will be presented at each GTTC meeting.
- The working group will organize and chair
technical sessions pertaining to wind tunnel calibration as requested by
the GTTC.
WIND
TUNNEL FLOW QUALITY WORKING GROUP
SCOPE
Thrust
stands are used extensively to measure the propulsive forces generated by a
test article. For a variety of
reasons, several types of thrust stands, calibration methods, tare measurements
and uncertainty evaluations have evolved throughout industry, government and
academia. This group recognizes
the benefits of identifying standards and acceptable practices. It is the intent of the individuals of
this working group to pool their information and experiences to develop a
single source describing the major issues associated with thrust stand design
and operation. The source will
also provide a list of reference material to substantiate and enhance the
group's work. It is hoped that the
scope of the working group will become more focused on these major issues after
the initial overview topic is completed.
STRUCTURE
The
Thrust Stand Working Group was formed under the auspices of the AIAA Ground
Testing Technical Committee (GTTC).
The working group is staffed by selected volunteers from academia,
industry and government and is not limited to members of the GTTC or AIAA. The Chairperson for the working group
shall be a member of the GTTC and will be appointed by the GTTC
Chairperson. An individual's
service on the working group will continue until the objectives for which they
were selected have been completed.
OBJECTIVES
- Provide a forum for the members
to learn the thrust measurement methodologies of various organizations.
- Provide a forum for the members
to solve thrust stand measurement and/or calibration problems and to
obtain input on new ideas concerning thrust stands and their calibration.
- Provide a forum for the members
to discuss new ideas concerning the design, fabrication and operation of
thrust stands.
- Determine guidelines for
selecting a thrust stand type that is best suited to meet the objectives
of a particular application.
- Develop documentation for thrust
stand calibration, operation methodologies and design implications and requirements.
OPERATION
- The working group will meet at
least twice a year at the times and locations concurrent with scheduled
GTTC meetings.
- A formal report will be
presented at each GTTC meeting.
- The working group will organize
and chair technical sessions germane to the scope of the working group as
requested by the GTTC.
WORKING GROUP DOCUMENTS
Thrust Stand Guide – e-mail Mark.Cross@arnold.af.mil or Raymond.S.Castner@nasa.gov if you
are on the committee and would like access to this document.
E-mail submissions to
Mark.Cross@arnold.af.mil
or Raymond.S.Castner@nasa.gov
This
page was last updated 2/6/2008. Contact Julien Weiss with any
changes.