Squeeze Film Dynamics of Two-Phase Seals: Part II—Turbulent Flow

1994 ◽  
Vol 116 (3) ◽  
pp. 479-487 ◽  
Author(s):  
J. A. Yasuna ◽  
W. F. Hughes
Keyword(s):  
Turbulent Flow ◽  
Dynamic Model ◽  
Entire Range ◽  
Squeeze Film ◽  
Turbulent Regime ◽  
Two Phase ◽  
Thermal Transients ◽  
Face Seals ◽  
Laminar And Turbulent Flow

A previously developed dynamic model for two-phase face seals is extended to include turbulent flow. Thermal transients over the entire range of laminar and turbulent flow are considered for both parallel and tapered geometries. Inlet losses and choking are accounted for in the turbulent regime. Axial responses to perturbations from equilibrium are examined, and general criteria are discussed for predicting stable, unstable and bistable seal operation.

Squeeze Film Dynamics of Two-Phase Seals

1992 ◽  
Vol 114 (2) ◽  
pp. 236-246 ◽  
Author(s):  
J. A. Yasuna ◽  
W. F. Hughes
Keyword(s):  
Steady State ◽  
Dynamic Analysis ◽  
Operating Conditions ◽  
Squeeze Film ◽  
Transient Responses ◽  
Two Phase ◽  
Thermal Transients ◽  
Face Seals

A dynamic analysis of two-phase face seals including squeeze film effects and thermal transients is presented. Axial responses to perturbations from equilibrium for various sets of typical seal operating conditions are examined, and the sensitivity of these responses to certain parameters is discussed. Sample calculations indicate damped transient responses which often decay as steady state is approached asymptotically. In some cases, however, stable and unstable oscillations are observed.

Reversed Flow in Face Seals

1969 ◽  
Vol 91 (3) ◽  
pp. 427-433 ◽  
Author(s):  
H. J. Sneck
Keyword(s):  
Turbulent Flow ◽  
Reversed Flow ◽  
Parallel Surface ◽  
External Fluid ◽  
Face Seals ◽  
Laminar And Turbulent Flow

The stream surfaces for laminar and turbulent flow in parallel surface seals are analytically determined for the cases where the fluid separates from one of the solid boundaries. These stream surfaces are used to determine when there is an exchange of external fluid across the seal land as well as the rate of these exchanges.

Thermal Effects in Face Seals

1969 ◽  
Vol 91 (3) ◽  
pp. 434-437 ◽  
Author(s):  
H. J. Sneck
Keyword(s):  
Temperature Distribution ◽  
Turbulent Flow ◽  
Incompressible Fluid ◽  
Thermal Effects ◽  
Face Seal ◽  
Temperature Level ◽  
Face Seals ◽  
Laminar And Turbulent Flow ◽  
Parallel Surfaces

The laminar and turbulent flow of an incompressible fluid between the rotating parallel surfaces of a face seal is investigated analytically to determine the influence of conduction, convection, and dissipation on the temperature distribution. A method of estimating the general temperature level within the seal is suggested.

LIMITATIONS OF THE STOCHASTIC APPROACH IN TWO-PHASE TURBULENT FLOW CALCULATIONS

1996 ◽  
Vol 6 (2) ◽  
pp. 211-225 ◽  
Author(s):  
Keh-Chin Chang ◽  
Wen-Jing Wu ◽  
Muh-Rong Wang
Keyword(s):  
Turbulent Flow ◽  
Stochastic Approach ◽  
Two Phase

Inductor Saturation Compensation in Three-Phase Three-Wire Voltage-Source Converters via Inverse System Dynamics-I

2020 ◽  
Author(s):  
Ziya Özkan ◽  
Ahmet Masum Hava
Keyword(s):  
Dynamic Model ◽  
Dynamic Performance ◽  
Current Control ◽  
Inverse System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Two Phase ◽  
Inverse Dynamic ◽  
Three Phase ◽  
Steady State Current

In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control (CSCC) methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This paper proposes an inverse dynamic model based compensation (IDMBC) method to overcome these performance issues. Accordingly, a review of inductor saturation and core materials is performed, and the motivation on the use of saturable inductors is clarified. Then, two-phase exact modelling of the 3P3W VSC control system is obtained and the drawbacks of CSCC have been demonstrated analytically. Based on the exact modelling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a fictitious linear inductor system for linear current regulators to perform satisfactorily.

Sign in / Sign up

Export Citation Format

Share Document