Numerical Model of a Tandem Reciprocating Hydraulic Rod Seal

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Bo Yang ◽  
Richard F. Salant
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Fluid Mechanics ◽  
Contact Mechanics ◽  
Computational Procedure ◽  
Stroke Length ◽  
Lip Seal ◽  
Through Flow ◽  
Deformation Mechanics

A numerical model of a tandem reciprocating hydraulic rod seal, consisting of two elastomeric U cup seals, has been constructed. It is applicable to cases in which the stroke length is significantly larger than the seal width. The model consists of coupled steady state fluid mechanics, deformation mechanics, and contact mechanics analyses, with an iterative computational procedure. The behaviors of the two seals are coupled through the pressure∕density in the interseal region and through flow continuity. Results for a typical tandem seal are compared to those of a single seal and a double lip seal.

Numerical Model of a Tandem Reciprocating Hydraulic Rod Seal

2007 ◽  
Author(s):  
Bo Yang ◽  
Richard F. Salant
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Fluid Mechanics ◽  
Contact Mechanics ◽  
Computational Procedure ◽  
Lip Seal ◽  
Through Flow ◽  
Deformation Mechanics

A numerical model of a tandem reciprocating hydraulic rod seal, consisting of two elastomeric U cup seals, has been constructed. The model consists of coupled steady state fluid mechanics, deformation mechanics and contact mechanics analyses, with an iterative computational procedure. The behaviors of the two seals are coupled through the pressure/density in the inter-seal region and through flow continuity. Results for a typical tandem seal are compared with those of a single seal and a double lip seal.

Soft EHL Simulations of U-Cup and Step Hydraulic Rod Seals

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Bo Yang ◽  
Richard F. Salant
Keyword(s):  
Steady State ◽  
Fluid Mechanics ◽  
Contact Mechanics ◽  
Critical Speed ◽  
Thermal Analyses ◽  
Elastohydrodynamic Lubrication ◽  
Computational Procedure ◽  
Stroke Length ◽  
Deformation Mechanics ◽  
Rod Seals

A numerical soft elastohydrodynamic lubrication model of a reciprocating hydraulic seal has been used to simulate the performance of a U-cup seal and a step seal in a conventional actuator. The model consists of coupled steady state fluid mechanics, deformation mechanics, contact mechanics, and thermal analyses, with an iterative computational procedure. The results indicate that for a given seal roughness and stroke length there is a critical rod speed above which the seal will not leak. The critical speed is dependent on both seal roughness and sealed pressure.

Soft EHL Analysis of a Reciprocating Hydraulic Step Seal

2008 ◽  
Author(s):  
Bo Yang ◽  
Richard F. Salant
Keyword(s):  
Steady State ◽  
Fluid Mechanics ◽  
Contact Mechanics ◽  
Thermal Analyses ◽  
Elastohydrodynamic Lubrication ◽  
Computational Procedure ◽  
Deformation Mechanics

A numerical soft EHL (elastohydrodynamic lubrication) model of a reciprocating hydraulic step seal has been used to analyze seal performance. The model consists of coupled steady state fluid mechanics, deformation mechanics, contact mechanics and thermal analyses, with an iterative computational procedure. Results for a typical step seal are compared with those of a double lip U-cup seal.

Numerical Model of a Reciprocating Hydraulic Rod Seal

2006 ◽  
Vol 129 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Richard F. Salant ◽  
Nicholas Maser ◽  
Bo Yang
Keyword(s):  
Numerical Model ◽  
Fluid Mechanics ◽  
Contact Mechanics ◽  
Thickness Distribution ◽  
Computational Procedure ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Influence Coefficients ◽  
Mechanics Analysis ◽  
Deformation Mechanics

A numerical model of an elastomeric reciprocating hydraulic rod seal has been constructed. The model consists of coupled fluid mechanics, deformation mechanics, and contact mechanics analyses, with an iterative computational procedure. The fluid mechanics analysis consists of the solution of the Reynolds equation, using flow factors to account for surface roughness. Deformation of the seal is computed through the use of influence coefficients, obtained from an off-line finite element analysis. The contact mechanics analysis uses the Greenwood and Williamson model. The seal model is used to predict leakage rate, friction force, fluid and contact pressure distributions, and film thickness distribution. Results for a typical seal show that the seal operates with mixed lubrication, and the seal roughness plays an important role in determining whether or not the seal leaks.

The Numerical Analysis of Temperature Field During Moveable Induction Heating of Steel Plate

2012 ◽  
Vol 28 (02) ◽  
pp. 73-81
Author(s):  
Xue-biao Zhang ◽  
Yu-long Yang ◽  
Yu-jun Liu
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Numerical Model ◽  
Induction Heating ◽  
Temperature Difference ◽  
Steel Plate ◽  
Heating Process ◽  
Quasi Steady State ◽  
Initial State ◽  
Plate Temperature

In shipyards, hull curved plate formation is an important stage with respect to productivity and accuracy control of curved plates. Because the power and its distribution of induction heat source are easier to control and reproduce, induction heating is expected to be applied in the line heating process. This paper studies the moveable induction heating process of steel plate and develops a numerical model of electromagneticthermal coupling analysis and the numerical results consistent with the experimental results. The numerical model is used to analyze the temperature changing rules and the influences on plate temperature field of heating speed of moveable induction heating of steel plate, and the following conclusions are drawn. First, the process of moveable induction heating of steel plate can be divided into three phases of initial state, quasi-steady state, and end state. The temperature difference between the top and bottom surfaces of the steel plate at the initial state is the biggest; it remains unchanged at the quasi-steady state and it is the smallest at the end state. Second, obvious end effect occurs when the edges of the steel plate are heated by the inductor, which causes a decrease in temperature difference between the top and bottom surfaces of the steel plate that is unfavorable for formation of pillow shape plates. Third, with the increase of heating speed, the temperature difference between the top and bottom surfaces of the steel plate increases gradually.

Inverse Determination of Temperature-Dependent Thermal Conductivity Using Steady Surface Data on Arbitrary Objects

2000 ◽  
Vol 122 (3) ◽  
pp. 450-459 ◽  
Author(s):  
T. J. Martin ◽  
G. S. Dulikravich
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Steady State ◽  
Measurement Errors ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
Computational Procedure ◽  
Heat Fluxes ◽  
Computational Method ◽  
Transfer Coefficients

An inverse computational method has been developed for the nonintrusive and nondestructive evaluation of the temperature-dependence of thermal conductivity. The methodology is based on an inverse computational procedure that can be used in conjunction with an experiment. Given steady-state heat flux measurements or convection heat transfer coefficients on the surface of the specimen, in addition to a finite number of steady-state surface temperature measurements, the algorithm can predict the variation of thermal conductivity over the entire range of measured temperatures. Thus, this method requires only one temperature probe and one heat flux probe. The thermal conductivity dependence on temperature (k-T curve) can be completely arbitrary, although a priori knowledge of the general form of the k-T curve substantially improves the accuracy of the algorithm. The influence of errors of measured surface temperatures and heat fluxes on the predicted thermal conductivity has been evaluated. It was found that measurement errors of temperature up to five percent standard deviation were not magnified by this inverse procedure, while the effect of errors in measured heat fluxes were even lower. The method is applicable to two-dimensional and three-dimensional solids of arbitrary shape and size. [S0022-1481(00)01703-5]

scholarly journals Effect of Rotor Spacing and Duct Diffusion Angle on the Aerodynamic Performances of a Counter-Rotating Ducted Fan in Hover Mode

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1338
Author(s):  
Woo-Yul Kim ◽  
Santhosh Senguttuvan ◽  
Sung-Min Kim
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Figure Of Merit ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Flow Conditions ◽  
Thrust Coefficient ◽  
Ducted Fan ◽  
Aerodynamic Performances ◽  
Rotor Model

The aerodynamic performance of a counter-rotating ducted fan in hover mode is numerically analyzed for different rotor spacings and duct diffusion angles. The design of the counter-rotating fan is inspired by a custom-designed single rotor ducted fan used in a previous study. The numerical model to predict the aerodynamic performance of the counter-rotating ducted fan is developed by adopting the frozen rotor approach for steady-state incompressible flow conditions. The relative angle between the front and the rear rotor is examined due to the usage of the frozen rotor model. The results show that the variation of thrust for the different relative angles is extremely low. The aerodynamic performances are evaluated by comparing the thrust, thrust coefficient, power coefficient, and figure of merit (FOM). The thrust, thrust coefficient, and FOM slightly increase with increasing rotor spacing up to 200 mm, regardless of the duct diffusion angle, and reduce on further increase in the rotor spacing. The duct diffusion angle of 0° generates about 9% higher thrust and increases the FOM by 6.7%, compared with the 6° duct diffusion angle. The duct diffusion angle is highly effective in improving the thrust and FOM of the counter-rotating ducted fan, rather than the rotor spacing.

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