SATPC0038854 Tab 06 RDSS..pdf

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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

NASA SHARED SERVICES CENTER

RECOMMENDATION AND DETERMINATION TO SOLICIT FROM ONE SOURCE

OR BRAND NAME

PICK ONE

Sole Source:

☒I recommend that NASA, NASA Shared Services Center negotiate with Ohio State University only for the procurement of direct numerical simulation code for the simulation of stochastic, freestreamdisturbance environment in a 3D, high-speed wind tunnel nozzle. The total estimated cost of this effort is and the estimated period of performance or lead-time for delivery is 7/10/2025 - 9/30/2025.

OR

Brand Name Justification:

☐I recommend that NASA, NASA Shared Services Center negotiate only with vendors who can provide the subject band name from . for Enter Supply or Service to be procured. The total estimated cost of this effort is Enter Dollar amount and the estimated period of performance or lead-time for delivery is Date.

This recommendation is for the acquisition of supplies or services determined to be reasonably available from only one source/only one manufacture. Competition is impractical for the following reasons (please answer the questions below):

1. What are the reasons for soliciting only the suggested source/suggested brand name? Please provide the unique characteristics of the items or services along with the supporting rationale and the market research performed to substantiate your reason for the suggested source/brand name.

Special numerical algorithms are necessary to enable NASA’s simulations of the natural, stochasticdisturbance environment in three-dimensional (3D) high-speed wind tunnel nozzles, such as the 31 InchMach 10 Tunnel at NASA’s Langley Research Center. A substantial amount of prior validation, especiallyfor similar class of problems, is critical to have confidence into the accuracy of the simulation results andto allow preliminary estimates of the computational resources required for the targeted simulations. Thesubject Direct Numerical Simulation (DNS) codes has been used and validated by Prof.

Lian Duan at theOhio State University for both axisymmetric and quasi-2D nozzle flow configurations of direct relevanceto NASA’s eventual target of digital wind tunnel capability for laminar-turbulent transition in conventional,high-speed wind tunnels. As both developers and users of the DNS codes, Prof.

Duan and his group at theOhio State University are uniquely qualified to support the applications of that code for NASA’ssimulations of the 31 Inch Mach 10 Tunnel, with a planned starting date at the beginning of FY26. Theircapability has been demonstrated in respected conference venues and peer-reviewed publications in toptierjournals.

2. What is the impact to the government if another vendor/brand is used? Include any dollar, schedule, or compatibility impacts if possible.

If another vendor were to be used, they will need to develop, validate, and document the DNS codes forthe specialized class of problems involving the simulations of natural acoustic disturbance environment inhigh-speed wind tunnels and to demonstrate a preliminary capability for digital wind tunnel simulations oflaminar-turbulent transition over a simple body shape, such as circular cone. This would represent aconsiderable effort and incur a substantial and prohibitive extra cost in terms of time and monetary value.Any delay in the procurement of adequately demonstrated capabilities would jeopardize NASA’s plans forthe simulation of freestream disturbance environment in the 31 Inch Mach 10 Wind Tunnel. Thus, thetimely availability of a suitable numerical code with an adequately demonstrated capability is critical tothe success of the NASA effort. Having worked with Prof. Duan and

Page 2 V2.0 3-15-2017 his team on related project, the NASAPage 2 V2.0 3-15-2017team is confident that Prof. Duan can deliver the code on time and provide adequate support andtroubleshooting during NASA applications, if necessary. Prof. Duan also has several utilities forpostprocessing the simulation results that will be provided with the code. Being written specifically for thetarget class of simulations, these utilities will significantly enhance the efficiency of the NASA effort. IfNASA had to develop and debug these scripts on its own (which would be necessary with another code ofthis type), it would amount an added impact on the project cost and schedule.

ADDITIONAL COMMENTS:

Technical User Name Date

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