Status Report

NASA ARC Solicitation: Risk Assessment of CLV Tank Catastrophic Explosion and Common Bulkhead Failure Scenario

By SpaceRef Editor
August 30, 2007
Filed under , , ,

Synopsis/Solicitation Combo – Aug 30, 2007
General Information
Solicitation Number: NNA07210699Q-AMG
Posted Date: Aug 30, 2007
FedBizOpps Posted Date: Aug 30, 2007
Original Response Date: Sep 12, 2007
Current Response Date: Sep 12, 2007
Classification Code: B — Special studies and analysis – not R and D
NAICS Code: 541710 – Research and Development in the Physical, Engineering, and Life Sciences

Contracting Office Address

NASA/Ames Research Center, JA:M/S 241-1, Moffett Field, CA 94035-1000


This notice is a combined synopsis/solicitation for commercial items prepared in accordance with the format in FAR Subpart 12.6, as supplemented with additional information included in this notice. This announcement constitutes the only solicitation; offers are being requested and a written solicitation will not be issued.

This notice is being issued as Request for Quotations (RFQ) for a risk assessment of CLV Tank Catastrophic Explosion and Common Bulkhead Failure Scenarios. This assessment will require two parts.

Part 1: Model Enhancement for CLV Tank Explosion Scenarios. Work requirements: 1. Simulations to support risk assessment of the catastrophic disintegration of the CLV tank and the ensuing explosion risk are currently in progress. The work in this part requires performing simulations based on enhanced phase change models that more accurately model the physical scenario and include phase change due to a combination of flashing and heat transfer.

Part 2: Risk Assessment of Common Bulkhead Failure Scenarios. Work Requirements: The risk scenarios to be assessed result from the failure of the baffle separating the two sections of the tank and leading to mixing between the LH2, LOX and the Oxygen vapor and Helium gas that are used to pressurize the LOX and LH2 respectively. Simulations are needed to accurately model these phenomena at various points in the launch trajectory from lift-off (when the tank is stationary) and in the subsonic, supersonic and hypersonic regimes as the vehicle gains speed and altitude.

It is anticipated that a systematic study of the risk scenarios would involve simulations at various points in the vehicle trajectory that are characterized by very different vaporization and combustion characteristics. These should include the following:

1. Modeling common bulkhead failure on the launch pad: Here the tank is stationary at ground level. Gravity is expected to play a significant role in the mixing between the fluids. The following simulations are required: (1) mixing, vaporization and pressure rise in the tank due to baffle failure, (2) the parametric study of venting from the tank due to cracks from over-pressurization, with ensuing combustion. This could be performed by specifying vent hole configurations at different locations and modeling of the flow through the vent holes. Additionally, studies of slow external leaks from the tank while atmospheric air is available for combustion are also desired. 2. Modeling common bulkhead at different altitudes and vehicle speeds: simulations of baffle failure at different operating points must be performed. The speed of the tank as well as the ambient pressure will vary depending on the altitude. Another important change will be the volume of liquid in the tanks. After the upper stage engine fires, the volume of liquid propellant in the tank will deplete. Therefore, the interaction process will be very different and could also lead to sloshing of the liquid in the tank (as discussed in number 3 below). 3. Evaluation of liquid sloshing due to vehicle acceleration: After the upper stage engine ignites at some point in the vehicle trajectory, the propellant in the tank will start to deplete. As the volume of liquid reduces, more space is available in the tank for the liquid to slosh and generate large dynamic loads on the baffle. A preliminary evaluation of sloshing can be conducted by providing a displacement to the liquid interface to generate an initial instability. The subsequent movement/ sloshing of the liquid interface can be tracked numerically. The preliminary evaluation could be conducted for one trajectory point where the risk of sloshing is expected to be high. 4. Assessment of requirements for unsteady/transient simulations of CLV tank with acceleration: A study needs to be conducted to evaluate the importance of unsteady acceleration from a risk assessment perspective. This study should result in a good understanding of the physics of the phenomena that needs to be captured/modeled and the requirements and methodology for accurate simulations.

The provisions and clauses in the RFQ are those in effect through FAC 05-18.

The NAICS Code and the small business size standard for this procurement are 541710 and 1,000 respectively. The offeror shall state in their offer their size status for this procurement.

All responsible sources may submit an offer which shall be considered by the agency.

Delivery to NASA Ames Research Center, Receiving Station m/s 255-3 Moffett Field, CA 94035-1000 is required within 305 days ARO. Delivery shall be FOB Destination.

The DPAS rating for this procurement is DO-C9.

Offers for the items(s) described above are due by September 12,2007 to NASA Ames Research Center Acquisition Division JAZ Attn: Christine M. Benavides Mail stop 241-1 Moffett Field, CA 94035 and must include, solicitation number, FOB destination to this Center, proposed delivery schedule, discount/payment terms, warranty duration (if applicable), taxpayer identification number (TIN), identification of any special commercial terms, and be signed by an authorized company representative. Offerors are encouraged to use the Standard Form 1449, Solicitation/Contract/Order for Commercial Items form found at URL:

Offerors shall provide the information required by FAR 52.212-1 (SEPT 2006), Instructions to Offerors-Commercial Items, which is incorporated by reference.

If the end product(s) offered is other than domestic end product(s) as defined in the clause entitled “Buy American Act — Supplies,” the offeror shall so state and shall list the country of origin.

FAR 52.212-4 (FEB 2007), Contract Terms and Conditions-Commercial Items is applicable.

FAR 52.212-5 (JUNE 2007), Contract Terms and Conditions Required To Implement Statutes or Executive Orders-Commercial Items is applicable and the following identified clauses are incorporated by reference: 52.222-3, 52.222-19, 52.222-21, 52.222-26, 52.222-35, 52.222-36, 52.222-37, 52.225-1, 52.225-13, and 52.232-34.

The FAR may be obtained via the Internet at URL:

The NFS may be obtained via the Internet at URL:

All contractual and technical questions must be in writing (e-mail or fax) to Christine M. Benavides at not later than September 5, 2007. Telephone questions will not be accepted.

Selection and award will be made to that offeror whose offer will be most advantageous to the Government, with consideration given to the factors of proposed technical merit, price, and past performance. Other critical requirements: All shipping costs shall be included in the quotation within the tasks and quotation marked as freight included shall also be considered. It is critical that offerors provide adequate detail to allow evaluation of their offer. (SEE FAR 52.212-1(b)).

Offerors must include completed copies of the provision at 52.212-3, Offeror Representations and Certifications – Commercial Items with their offer. These may be obtained via the internet at URL: . These representations and certifications will be incorporated by reference in any resultant contract.

An ombudsman has been appointed — See NASA Specific Note “B”.

Prospective offerors shall notify this office of their intent to submit an offer. It is the offeror’s responsibility to monitor the following Internet site for the release of solicitation amendments (if any): . Potential offerors will be responsible for downloading their own copy of this combination synopsis/solicitation and amendments (if any).

Any referenced notes may be viewed at the following URLs linked below.

Point of Contact

Name: Christine M Benavides
Title: Purchasing Agent
Phone: 650-604-5807
Fax: 650-604-0932

Name: Marianne Shelley
Title: Contracting Officer
Phone: 650-604-4179
Fax: 650-604-0932

SpaceRef staff editor.