Multi-objective optimization of no-slip and super-slip spiral groove upstream pumping liquid film seal under wide operating conditions

To enhance the comprehensive performance of the spiral groove upstream pumping liquid film seal (SG-UPLFS) under wide operating conditions, a super-slip groove design and multi-objective optimization study were conducted. Within the operational range of rotational speeds N = 1000– 10,000 r/min and pressure differentials Δ P = 0–5 MPa, a multi-objective genetic algorithm (MOGA) was employed to perform multi-objective optimization of groove structural parameters, with the objectives of maximizing the opening force F o and maximizing the pumping rate Q P (equivalent to minimizing the leakage rate Q L ). Pareto optimal solution sets were obtained across different N and Δ P ranges. The results indicate that within the specified rotational speed range, the pump-opening product Φ (= F o × Q P ) of the pareto optimal solution set for super-slip (POSS) achieved a maximum improvement of 70.93% compared to the pareto optimal solution set for no-slip (PONS). Under varying pressure differentials, the maximum increase in F o for POSS reached 45.27%, Q P increased by 290.32%, and Q L decreased by 82.88% at Δ P = 5 MPa, although its advantage over the original SS design is condition-dependent. The optimized operating film thickness h 0 ranged from 3.1 to 5.1 μm. The optimal structural parameters were determined as follows: groove depth h g = 4.3–7.3 μm, spiral angle α = 9–12°, groove width ratio β = 0.43–0.67, and groove diameter ratio γ = 0.59–0.83. The optimized super-slip groove design improves SG-UPLFS performance under wide operating conditions by enhancing pumping and leakage resistance.