Influence of squeezing behavior on cavitation characteristics and performance parameters of mechanical seals with an efficient mass-conserving algorithm

Abstract

The purpose of this paper is to investigate the influence of squeezing and traction effects on the sealing performance of spiral groove mechanical seals. Firstly, a modified algorithm is proposed to solve the Reynolds equation with squeeze term and mass-conserving boundary conditions, which could effectively improve the calculation efficiency with high accuracy. Then, squeeze effect is put forward to analyze the cavitation characteristic at different boundary conditions and pressure distribution with various squeeze velocities. Finally, the squeeze effect on seal performance, i.e., fluid bearing capacity, clearance flow and cavitation region, under different operating conditions and structural parameters, is discussed. Results indicate that the traction effect has relatively apparent impact than squeeze effect on pressure and flow rate variation. Squeeze effect becomes less visible when the rotational speed exceeds 3000 r/min and film thickness or groove depth exceeds 20 μm. This result would contribute to revealing the feature of transient flow and dynamic response during unsteady conditions.

Lubrication and stability enhancement by attaching superconducting magnetic force on non-contacting mechanical seals for reusable rocket turbopump

“…The geometric and operating parameters of the two sealing structures are chosen as in Table 1. 12,20,21 The performance and stability improvement through attaching magnetic force are analyzed at different aspects, including the influence of turbulence and cavitation, flow characteristics considering misalignment, and transient response under pressure fluctuation. Firstly, the cavitation rate of the two sealing structures is <2% from 8000 to 22,000 r/min when only the cavitation effect is taken into consideration.…”

“…Therefore, this novel structure will not affect the whole space size or weight while improving the bearing capacity. Many typical parameters, such as α, r i , r o , p i , and p o , 21 have been explained in previous articles. r g1 and r g2 represent the herringbone grooves radii at the inner and outer sides, respectively.…”

“…The fluid pressure of LOX is governed by the lubrication equation, and it is necessary to take turbulence and cavitation into consideration due to high speed and pressure. [19][20][21]29 The modified Reynolds equation is established as follows:…”

“…The detailed solution procedure is given in Xu et al 21 and Ausas et al 29 The turbulence factors k θ and k r 11 are proposed by using the Ng-Pan 30 model as follows:…”

Thermo-Hydrodynamic Lubricating Behaviors of Upstream Liquid Face Seals with Ellipse Dimples

“…Over the past decades, published works have shown that geometric grooves with upstream pumping capabilities were feasible for achieving a zero-leakage design of the sealed medium [8][9][10][11][12][13][14]. In 1984, Etsion [8] pointed out that the effective design of grooves on the sealing surface might contribute to achieving zero leakage.…”