Numerical comparisons of rotordynamic characteristics for three types of labyrinth gas seals with inlet preswirl

Li, Zhigang; Li, Jun; Feng, Zhenping

doi:10.1177/0957650916668768

Cited by 16 publications

(8 citation statements)

References 26 publications

(54 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thorat and Chids showed that the whirl frequency depends significantly on the DC of the labyrinth seals when the Mach number approaches unity [38], or when there is an inlet pre-swirl or when the pressure is very high [38,39]. Additionally, pre-swirl and the rotor whirl speeds have a small effect on the leakage for one-sided and stepped labyrinths [29].…”

Section: Cfd Model Setupmentioning

confidence: 99%

A Design of the Compression Chamber and Optimization of the Sealing of a Novel Rotary Internal Combustion Engine Using CFD

Savvakis¹,

Mertzis²,

Nassiopoulos³

et al. 2020

Energies

View full text Add to dashboard Cite

The current paper investigates two particular features of a novel rotary split engine. This internal combustion engine incorporates a number of positive advantages in comparison to conventional reciprocating piston engines. As a split engine, it is characterized by a significant difference between the expansion and compression ratios, the former being higher. The processes are decoupled and take place simultaneously, in different chambers and on the different sides of the rotating pistons. Initially, a brief description of the engine’s structure and operating principle is provided. Next, the configuration of the compression chamber and the sealing system are examined. The numerical study is conducted using CFD simulation models, with the relevant assumptions and boundary conditions. Two parameters of the compression chamber were studied, the intake port design (initial and optimized) and the sealing system size (short and long). The best option was found to be the combination of the optimized intake port design with the short seal, in order to keep the compression chamber as close as possible to the engine shaft. A more detailed study of the sealing system included different labyrinth geometries. It was found that the stepped labyrinth achieves the highest sealing efficiency.

show abstract

Section: Cfd Model Setupmentioning

confidence: 99%

A Design of the Compression Chamber and Optimization of the Sealing of a Novel Rotary Internal Combustion Engine Using CFD

Savvakis¹,

Mertzis²,

Nassiopoulos³

et al. 2020

Energies

View full text Add to dashboard Cite

show abstract

“…Based on the porous medium model and whirling rotor method, Zhang et al [22] revealed the effects of operating conditions on rotor dynamic coefficients for the different seal configurations by the numerical model. Wu et al [23] employed the multi-frequency dynamic mesh technique by Li [24] to calculate the dynamic characteristics of various types of seals. Their research examined changes in the dynamic characteristics of different seals, ranging from sub-frequency to super-frequency whirl.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigations of Static and Dynamic Characteristics of a Novel Staggered Labyrinth Seal with Semi-Elliptical Structure

Yan,

Ye,

Wang

et al. 2024

Lubricants

View full text Add to dashboard Cite

In order to optimize sealing performance, a novel labyrinth seal with semi-elliptical teeth (SET) structure is proposed in this paper, which includes semi-elliptical teeth and a series of cavities. The simulation results calculated by the numerical methods are compared with the experimental and theoretical results, and static and dynamic characteristics of the novel SET structure are further investigated. The numerical simulations of labyrinth seals with the SET structure demonstrate high accuracy and reliability, with a maximum relative error of less than 6% as compared to experimental results, underscoring the validity of the model. Notably, leakage rates are directly influenced by pressure drop and axial offset, with optimal sealing achieved at zero axial displacement. The direct damping coefficient increases as the pressure drop increases while the other dynamic coefficients decrease. Additionally, the stability results show that the novel SET structure exhibits higher stability for positive axial offsets. The novel model and corresponding results can provide a meaningful reference for the study of sealing structure and coupled vibration in the field of fluid machinery.

show abstract

“…For high pressure and high rotational speed turbomachinery where stability is of concern, because of the limited effective damping offered by labyrinth seal, 6 pocket damper seals were invented and first tested by Vance and Schultz. 7 Different from the labyrinth seal, the pocket damper seals insert or machine partition walls equally spaced around the circumference.…”

Section: Introductionmentioning

confidence: 99%

Rotordynamic characteristics of a novel labyrinth seal with partition walls and helical groove teeth

Xue,

Fang,

Wang

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part A:

Self Cite

View full text Add to dashboard Cite

To improve the stability of the conventional labyrinth seal (LS), in this paper, four novel fully partitioned helically labyrinth seals (FPHGLS) were designed and they were in comparison with one FPPGLS. The influences of the preswirl ratio and the helical groove pitch on the leakage flow and rotordynamic characteristics were numerically investigated, using the transient computational fluid dynamics (CFD) method based on the multi-frequency elliptical whirling orbit model. The accuracy and availability of the present transient numerical method were demonstrated based on the experiment data. The results show that the partition walls design can significantly increase the direct damping and cross-coupling stiffness for labyrinth seals and the helical teeth design can significantly decrease the cross-coupling stiffness and tangential force. When the helical groove pitch is equal to the seal length, the leakage nearly remains unchanged. Compared to the baseline design (LS), the FPPGLS and the FPHGLS have similar and significantly larger direct stiffness and direct damping. The two designs possess positive direct stiffness throughout the frequency range. The FPPGLS and FPHGLS possess significantly higher direct damping (∼323.7% larger than LS). But the FPPGLS possesses the largest cross-coupling stiffness among three seals at two preswirl ratios. From preswirl ratio = 0.13–0.84, the cross-coupling stiffness of the FPHGLS decreases by 53.4-310.1% compared with the FPPGLS. Increasing the helical groove pitch increases both direct stiffness and direct damping and reduces cross-coupling stiffness, but it also leads to greater leakage losses. In general, the novel FPHGLS whose helical groove pitch is equal to seal length possesses superior rotordynamic characteristics and similar leakage characteristic. This work provides the reference of the seal design and safety operation for the turbomachinery.

show abstract

Numerical comparisons of rotordynamic characteristics for three types of labyrinth gas seals with inlet preswirl

Cited by 16 publications

References 26 publications

A Design of the Compression Chamber and Optimization of the Sealing of a Novel Rotary Internal Combustion Engine Using CFD

A Design of the Compression Chamber and Optimization of the Sealing of a Novel Rotary Internal Combustion Engine Using CFD

Numerical Investigations of Static and Dynamic Characteristics of a Novel Staggered Labyrinth Seal with Semi-Elliptical Structure

Rotordynamic characteristics of a novel labyrinth seal with partition walls and helical groove teeth

Contact Info

Product

Resources

About