Calculation of Piston Ring Radial Pressure Distribution from its Measured Free Shape

Tomanik, Eduardo; Bruno, Rafael Antonio

doi:10.4271/2012-01-1322

Cited by 7 publications

(7 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides, computationally our model is slightly more advantageous since we do not have to evaluate the external thermal load at each iteration of the Newton-Raphson algorithm but we just change the free shape curvature and the initial loads accordingly before iterating. Circumferential Direction (degree) Circumferential Direction (degree) In the rest of this section we keep using the same parameters mentioned previously except for the ring free shape that is no longer designed to have uniform pressure distribution at a round shape with a ring tension of 25.4N but instead we use the TC design developed by Mahle and studied by Tomanik [47]. The corresponding free shape and curvature are given in As we can see this ring is designed to have the highest curvature at the tips and a decreasing radial coordinate when we are close to them.…”

Section: Tkcrma Mmnr-rrt Effetmentioning

confidence: 99%

“…Each data set corresponds to a certain pressure distribution and therefore to a specific ovality and free shape. Tomanik presented a theoretical study and experimental procedure to characterize the free shape and ovality of these two ring types [47]. We call these data sets by the Usual and the TC one, using the same nomenclature given to the rings.…”

Section: Validation Of the Four Modelsmentioning

confidence: 99%

“…Besides the theoretical force distribution, Mahle provided us with measured ovality for the usual and the TC cases that has been used in Tomanik's work [47]. In this section we will present the results obtained from our model using these experimental data sets.…”

Section: Validation Of the Model Using Ovality Measurementmentioning

confidence: 99%

See 2 more Smart Citations

Curved Beam Based Model for Piston-Ring Designs in Internal Combustion Engines: Closed Shape Within a Flexible Band, Free-Shape and Force in Circular Bore Study

Bhouri

Tian

2018

SAE Technical Paper Series

View full text Add to dashboard Cite

Characterizing the piston ring behavior is inherently associated with the oil consumption, friction, wear and blow-by in internal combustion engines. This behavior varies along the ring's circumference and determining these variations is of utmost importance for developing ring-packs achieving desired performances in terms of sealing and conformability. This study based on straight beam model was already developed but does not consider the lubrication sub-models, the tip gap effects and the characterization of the ring free shape based on any final closed shape. In this work, three numerical curved beam based models were developed to study the performance of the piston ring-pack. The conformability model was developed to characterize the behavior of the ring within the engine. In this model, the curved beam model is adopted with considering ring-bore and ring-groove interactions. This interactions include asperity and lubrication forces. Besides, gas forces are included to the model along with the inertia and initial ring tangential load. In this model we also allow for bore, groove upper and lower flanks thermal distortion. We also take into account the thermal expansion effect of the ring and the temperature gradient from inner diameter (ID) to outer diameter (OD) effects. The piston secondary motion and the variation of oil viscosity on the liner with its temperature in addition to the existence of fuel and the different hydrodynamic cases (Partially and fully flooded cases) are considered as well. This model revealed the ring position relative to the groove depending on the friction, inertia and gas pressures. It also characterizes the effect of non-uniform oil distribution on the liner and groove flanks. Finally, the ring gap position within a distorted bore also reveals the sealing performance of the ring. Using the curved beam model we also developed a module determining the twist calculation under fix ID or OD constraint. The static twist is an experimental characterization of the ring during which the user taps on the ring till there is a minimum clearance between the ring lowest point and the lower plate all over the ring's circumference but without any force contact. Our last model includes four sub-models that relate the ring free shape, its final shape when subjected to a constant radial pressure (this final shape is called ovality) and the force distribution in circular bore. Knowing one of these distribution, this model determines the other two. This tool is useful in the sense that the characterization of the ring is carried out by measuring its ovality which is more accurate than measuring its free shape or force distribution in circular bore. Thus, having a model that takes the ovality as an input is more convenient and useful based on the experiments carried out to characterize the ring.

show abstract

Section: Tkcrma Mmnr-rrt Effetmentioning

confidence: 99%

Section: Validation Of the Four Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Curved Beam Based Model for Piston-Ring Designs in Internal Combustion Engines: Closed Shape Within a Flexible Band, Free-Shape and Force in Circular Bore Study

Bhouri

Tian

2018

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…Liu beam elements with consideration of the ring lapping process [9]. Tomanik and Bruno developed a ring radial force distribution measurement method with pin gauge that shows the contact force variations at different circumferential locations [10]. Tomanik also proposed a new criterion for ring conformability [11].…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Piston Ring–Cylinder Bore Contact Modeling

Cheng

Kharazmi

Schock

et al. 2015

Journal of Engineering for Gas Turbines and Power

View full text Add to dashboard Cite

Increasing durability, preventing knocking combustion, improving fuel efficiency, and reducing pollutant emission characterize the needs for modern internal combustion engine design. These factors are highly influenced by the power cylinder system design. In particular, the piston ring to cylinder bore contact force distribution around the circumference of the piston rings must be optimized under all running conditions. To accomplish this, the ring manufacturers make the ring curvature nonconstant along the circumference. Most existing analytical tools are not able to simulate the variation along the ring circumference. In order to improve the understanding of this contact distribution and provide a high-fidelity ring design tool, a three-dimensional finite element piston ring model was developed to accomplish this variation. The modeling procedure and results are presented in this work. Experiments using a commercially available ring with negative ovality were conducted to validate the model. The ring free-shape profile and the ring cross section geometries were used as inputs to the model. Typical piston ring groove and cylinder wall temperatures were also model inputs to characterize thermal influences on the ring/bore interface forces. The ring/bore conformability was analyzed as a function of the ring radial displacements, cylinder bore constraint forces and thermal load changes to the ring. The model output showed radially separation gaps between the ring front face and the bore. This analysis provides an insight to evaluate the piston ring design. Together with an optimizer, the model can be used as a ring design tool to predict the ring free shape with a specified constraint force distribution pattern. Examples are given to demonstrate the capabilities of this numerical analytical tool. In addition, the 3D ring model can be used to improve the accuracy of existing lubrication, friction, and wear analysis tools and therefore improve the entire internal combustion engine power cylinder system design.

show abstract

“…Liang Liu and Tian Tian presented an analytical tool for the ring conformability calculation using space beam elements with consideration of the ring lapping process [9]. Eduardo Tomanik and Rafael Bruno developed a ring radial force distribution measurement method with pin gauge that shows the contact force variations at different circumferential locations [20]. Tomanik also proposed a new criterion for ring conformability [19].…”

Section: Introductionmentioning

confidence: 99%

Modeling of Piston Ring-Cylinder Bore-Piston Groove Contact

Cheng

Kharazmi

Schock

2015

SAE Technical Paper Series

View full text Add to dashboard Cite

A three-dimensional piston ring model has been developed using finite element method with eight-node hexahedral elements. The model predicts the piston ring conformability with the cylinder wall as well as the separation gap between the interfaces if existing in the radial direction. In addition to the radial interaction between the ring front face and the cylinder wall, the model also predicts the contact between the ring and groove sides in the axial direction. This means, the ring axial lift, ring twist, contact forces with the groove sides along the circumferential direction are all calculated simultaneously with the radial conformability prediction. The ring/groove side contact can be found for scraper ring at static condition, which is widely used as the second compression ring in a ring pack. Thermal load is believed having significant influence on the ring pack performance. This thermal load influence is included in the model with a typical piston ring groove and cylinder wall temperature boundary condition. The modeling procedure and results are presented in this work. The model analyzes the piston ring performance with the consideration of the variation along the ring circumference, which has not been considered by the two-dimensional models widely used currently. This work describes a three-dimensional (3D hereafter) analytical ring model to address the pressure/force distribution between the ring-cylinder bore interface along the ring circumference direction. In

show abstract

Calculation of Piston Ring Radial Pressure Distribution from its Measured Free Shape

Cited by 7 publications

References 5 publications

Curved Beam Based Model for Piston-Ring Designs in Internal Combustion Engines: Closed Shape Within a Flexible Band, Free-Shape and Force in Circular Bore Study

Curved Beam Based Model for Piston-Ring Designs in Internal Combustion Engines: Closed Shape Within a Flexible Band, Free-Shape and Force in Circular Bore Study

Three-Dimensional Piston Ring–Cylinder Bore Contact Modeling

Modeling of Piston Ring-Cylinder Bore-Piston Groove Contact

Contact Info

Product

Resources

About