# SAM #DARPA-PS-26-136

DARPA Solicitation for Extreme-Scale Hydrodynamics Research ('Fox Tail')

**Buyer:** DEF ADVANCED RESEARCH PROJECTS AGCY
**Posted:** September 24, 2026
**Respond By:** January 29, 2027
**Identifier:** DARPA-PS-26-136
**NAICS:** 541715

DARPA is seeking innovative research proposals for extreme-scale hydrodynamics under the 'Fox Tail' program.
- Government Buyer:
  - Defense Advanced Research Projects Agency (DARPA)
  - Advanced Research Projects Agency (DEF ADVANCED RESEARCH PROJECTS AGCY), Arlington, VA
- OEMs and Vendors:
  - No specific OEMs or vendors are mentioned
- Products/Services Requested:
  - Theoretical and computational modeling approaches for:
    - High amplitude wave propagation
    - Very high Reynolds number flows
    - Abrupt phase changes
  - Emphasis on first principles-based closures of governing laws of fluid motion under extreme conditions
- Unique/Notable Requirements:
  - Focus on innovative, first principles-based modeling
  - Solicitation titled 'Fox Tail' (DARPA-PS-26-136)
  - No specific products, part numbers, or quantities provided
- Opportunity is for advanced research, not product procurement

### Description

The Defense Advanced Research Projects Agency (DARPA) is soliciting innovative proposals in the general area of extreme-scale hydrodynamics, including, but not limited to, high amplitude wave propagation, very high Reynolds number flows, and abrupt phase changes. Proposed research should investigate innovative theoretical and computational modeling approaches relying on first principles-based closures of the governing laws of fluid motion under such conditions.

[View original listing](https://sam.gov/opp/544aaeb3e0a148d1be7c36ca60d9e844/view)