A Navier-Stokes-Based Validity Framework for Linear and Nonlinear Transient Pressure-Wave Modeling in Spacecraft Pumped-Fluid Loops

Misha Nikouravan (Author) — Tue, 15 Sep 2026 00:00:00 +0000

Transient pressure disturbances in spacecraft pumped-fluid loops are commonly represented by linearized one-dimensional models, yet the error introduced by linearization is rarely quantified against a nonlinear formulation derived from the same conservation laws. This study develops a Navier-Stokes-based validity framework for single-phase spacecraft pumped-fluid loops. Mass conservation and axial momentum balance for a slightly compressible Newtonian liquid are reduced to coupled pressure-velocity equations that retain convective inertia and flow-regime-dependent wall friction. A consistent linear model is obtained by perturbation about a nonzero steady circulation state. The equations are solved with fourth-order spatial differencing and classical fourth-order Runge-Kutta integration. Verification against an exact smooth nonlinear characteristic solution gives the designed fourth-order convergence, with relative error decreasing to 2.72×10⁻¹⁰ at 800 grid points, and the nonlinear solution recovers the moving-base linear limit as the acoustic Mach number tends to zero. Two spacecraft-informed applications are examined: a turbulent HFE-7200 external thermal-control loop and a laminar 50/50 propylene-glycol/water internal loop. For a 20% smooth pump disturbance, the global linear-versus-nonlinear pressure discrepancies are 0.0667% and 0.0116%, respectively, with peak transient pressure excursions of approximately 74.8 and 13.6 kPa. Even at the largest tested disturbance amplitude (45%), the discrepancies remain 0.1481% and 0.0260%. A broader dimensionless map shows that errors above 1% require simultaneously larger acoustic Mach number and disturbance amplitude, while the 5% threshold in the tested turbulent family appears only near M ≳ 0.08 with strong forcing. The results show that the consistent linear model is quantitatively sufficient for the representative low-Mach spacecraft loops studied, while the nonlinear formulation provides a verified criterion for identifying conditions under which that simplification ceases to be adequate.

Another Take on the Musakhail-Farmer Gravitational Aether: The Krueger-Farmer Gravitational Aether

James Russell Farmer (Author) — Tue, 15 Sep 2026 00:00:00 +0000

This paper examines the proposed roles of the Higgs boson and the Reverse Higgs boson in relation to metallic lattice states and gravitational aether. The Higgs boson is treated as producing protons from positrons, whereas the Reverse Higgs boson is associated with conversions between massive fermions and photons. Three possible metallic-lattice configurations are considered: the spherical metallic photon, the Bohr atom, and the Thomson atom. These states are then related to a proposed duality between Newtonian gravitational force and Einsteinian space-time curvature. Within the model, gravitational force is associated with nuclei and with gravitons propagating along tensioned electromagnetic field lines. When a nucleus is absent at the field point, residual space-time curvature remains and acts on non-nuclear entities. Spherical metallic photons and Thomson atoms are therefore assigned a “phantom nucleus” so that they can function as gravitational sources. The Krueger-Farmer gravitational-aether interpretation is developed by relating gravitational interaction to nuclear motion and to two closely spaced characteristic frequencies. The paper also compares four states of matter, including the Schrödinger atom, and examines de Broglie relations, fermionic-wave amplitude, multiple-electron Bohr atoms, and non-orthogonality of Bohr orbits. Finally, the proposed graviton mass-speed relation is compared with the uncertainty principle in an attempt to connect quantum mechanics with gravity within the author’s M-theory framework.

Hyperscience International Journals

A Navier-Stokes-Based Validity Framework for Linear and Nonlinear Transient Pressure-Wave Modeling in Spacecraft Pumped-Fluid Loops

Another Take on the Musakhail-Farmer Gravitational Aether: The Krueger-Farmer Gravitational Aether