Open Access

Júlia Belmonte Fortuny

• To date, many experiments have been performed to study how the internal geometrical shapes of the annular liquid seal can reduce internal leakage and increase pump efficiency. These can be time-consuming and expensive as all rotordynamic coefficients must be determined in each case. Nowadays, accurate simulation methods to calculate rotordynamic coefficients of annular seals are still rare.To date, many experiments have been performed to study how the internal geometrical shapes of the annular liquid seal can reduce internal leakage and increase pump efficiency. These can be time-consuming and expensive as all rotordynamic coefficients must be determined in each case. Nowadays, accurate simulation methods to calculate rotordynamic coefficients of annular seals are still rare. Therefore, new numerical methods must be designed and validated for annular seals. The present study aims to contribute to this labour by providing a summary of the available test rig and seals dimensions and experimental results obtained in the following experiments: − Kaneko, S et al., Experimental Study on Static and Dynamic Characteristics of Liquid Annular Convergent-Tapered Seals with Honeycomb Roughness Pattern (2003) [1] − J. Alex Moreland, Influence of pre-swirl and eccentricity in smooth stator/grooved rotor liquid annular seals, static and rotordynamic characteristics (2016) [2] A 3D CAD simulation with Siemens NX Software of the test rig used in J. Alex Moreland’s experiment has been made. The following annular liquid seals have also been 3D modelled, as well as their fluid volume: − Smooth Annular Liquid Seal (SS/GR) (J. Alex Moreland experiment) − Grooved Annular Liquid Seal (GS/SR) − Round-Hole Pattern Annular Liquid Seal (𝐻𝑑=2 mm) (GS/SR) − Straight Honeycomb Annular Liquid Seal (GS/SR) − Convergent Honeycomb Annular Liquid Seal (No. 3) (GS/SR) − Smooth Annular Liquid Seal (SS/SR) (S. Kaneko experiment) In the case of the seals used in S. Kaneko’s experiments, the test rig has been adapted to each seal, defining interpart expressions which can be easily modified. Afterwards, it has been done a CFD simulation of the Smooth Annular Liquid Seal using Ansys CFX Software. To do so, the fluid volume geometry has been simplified to do a first approximation. Results have been compared for an eccentricity 𝜀0=0.00 for the following ranges of rotor speeds and differential of pressure: − Δ𝑃= 2.07, 4.14, 6.21, and 8.27 bar, − 𝜔= 2, 4, 6 and 8 krpm. Even results obtained have the same trend as the one proportionated by the literature, they cannot be validated as the error is above 5%. It is also observed that as the pressure drop increases, the relative error decreases considerably.…