Evaluation of the Effect of Gas Leakage on Operation of an Optical Engine

2010 ◽  
Author(s):  
E. Kapusuz ◽  
B. Ekici
Keyword(s):  
Gas Flow ◽  
Combustion Engine ◽  
Numerical Study ◽  
Mass Loss Rate ◽  
Ic Engine ◽  
Gas Leakage ◽  
Engine Model ◽  
Optical Engine ◽  
Laser Diagnostic ◽  
Flow Through

An experimental and numerical study is carried out to evaluate the significance of gas leakage for a non-lube optically accessible internal combustion engine and to obtain estimation for the gas flow out of the combustion chamber at each engine cycle and its effect on the in-cylinder component states during optical engine’s operation. Attention is paid to blow-by and circumferential flow through the gaps between the piston rings and the liner. Optical engines are typically operated without lubrication to avoid window fouling and generation of fluorescence by oil particles that interfere with laser diagnostic signals, in view of this circumstance significant blow-by is expected in optical engines due to lack of “wet-seal” on the cylinder walls which permits circumferential flow of gases through the piston ring pack region resulting in increased blow-by. Semi analytical model estimating the mass loss rate is incorporated into zero dimensional thermodynamic IC engine model which simulates in-cylinder processes. Predicted results are compared for leaking and non-leaking engine simulations.

Numerical Study on Characteristics of Real Gas Flow Through a Critical Nozzle

2012 ◽  
Vol 29 (1) ◽  
Author(s):  
Junji Nagao ◽  
Shigeru Matsuo ◽  
Mamun Mohammad ◽  
Toshiaki Setoguchi ◽  
Heuy Dong Kim
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Real Gas ◽  
Critical Nozzle ◽  
Flow Through

Study of the Influence of the Add оf Micropores on Filtering Characteristics of High Porous Structures

2020 ◽  
Vol 24 (9) ◽  
pp. 39-43
Author(s):  
O.V. Soloveva ◽  
S.A. Solovev ◽  
R.R. Yafizov
Keyword(s):  
Quality Factor ◽  
Particle Deposition ◽  
Gas Flow ◽  
Numerical Study ◽  
Total Porosity ◽  
Deposition Efficiency ◽  
Open Cell Foam ◽  
Flow Through ◽  
Highly Porous ◽  
Highly Porous Material

In this work we carried out a numerical study of the gas flow through an open cell foam material with solid-state partitions and partitions containing micropores. The effect of a geometry change by adding micropores on the pressure drop, particle deposition efficiency, and filter quality factor is estimated. The results showed that the addition of micropores positively affects the filtering and hydrodynamic properties of the highly porous material for the same macroporosity of the medium, and for the case of total porosity of the medium, the material with micropores allows one to obtain an increased value of the deposition efficiency and filter quality factor for small particles.

scholarly journals On the Transient Three-Dimensional Tribodynamics of Internal Combustion Engine Top Compression Ring

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
C. Baker ◽  
S. Theodossiades ◽  
R. Rahmani ◽  
H. Rahnejat ◽  
B. Fitzsimons
Keyword(s):  
Combustion Engine ◽  
Fuel Efficiency ◽  
Three Dimensional ◽  
Cylinder Liner ◽  
Internal Combustion ◽  
Ic Engine ◽  
Gas Leakage ◽  
Compression Ring ◽  
Frictional Losses ◽  
Harmful Emissions

There are increasing pressures upon the automotive industry to reduce harmful emissions as well as meeting the key objective of enhanced fuel efficiency, while improving or retaining the engine output power. The losses in an internal combustion (IC) engine can be divided into thermal and parasitic as well as due to gas leakage because of untoward compression ring motions. Frictional losses are particularly of concern at low engine speeds, assuming a greater share of the overall losses. Piston–cylinder system accounts for nearly half of all the frictional losses. Loss of sealing functionality of the ring pack can also contribute significantly to power losses as well as exacerbating harmful emissions. The dynamics of compression ring is inexorably linked to its tribological performance, a link which has not been made in many reported analyses. A fundamental understanding of the interplay between the top compression ring three-dimensional elastodynamic behavior, its sealing function and contribution to the overall frictional losses is long overdue. This paper provides a comprehensive integrated transient elastotribodynamic analysis of the compression ring to cylinder liner and its retaining piston groove lands' conjunctions, an approach not hitherto reported in the literature. The methodology presented aims to aid the piston ring design evaluation processes. Realistic engine running conditions are used which constitute international drive cycle testing conditions.

scholarly journals Mathematical Model of Piston Ring Sealing in Combustion Engine

2015 ◽  
Vol 21 (4) ◽  
pp. 66-78 ◽  
Author(s):  
Grzegorz Koszałka ◽  
Mirosław Guzik
Keyword(s):  
Mathematical Model ◽  
Heat Exchange ◽  
Numerical Solution ◽  
Gas Flow ◽  
Piston Ring ◽  
Combustion Engine ◽  
Cylinder Liner ◽  
Computer Application ◽  
Piston Rings ◽  
Flow Through

Abstract This paper presents a mathematical model of piston-rings-cylinder sealing (TPC) of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The paper contains descriptions of: assumptions used for developing the model, the model itself, its numerical solution as well as its computer application for carrying out simulation tests.

scholarly journals Modelling the delivery of dust from discs to ionized winds

2021 ◽  
Vol 502 (2) ◽  
pp. 1569-1578
Author(s):  
Richard A Booth ◽  
Cathie J Clarke
Keyword(s):  
Mass Loss ◽  
Gas Flow ◽  
Extreme Ultraviolet ◽  
Mass Loss Rate ◽  
Maximum Size ◽  
Simple Relation ◽  
Ionization Front ◽  
Order Of Magnitude ◽  
Novel Method ◽  
Flow Through

ABSTRACT A necessary first step for dust removal in protoplanetary disc winds is the delivery of dust from the disc to the wind. In the case of ionized winds, the disc and wind are sharply delineated by a narrow ionization front where the gas density and temperature vary by more than an order of magnitude. Using a novel method that is able to model the transport of dust across the ionization front in the presence of disc turbulence, we revisit the problem of dust delivery. Our results show that the delivery of dust to the wind is determined by the vertical gas flow through the disc induced by the mass-loss, rather than turbulent diffusion (unless the turbulence is strong, i.e. α ≳ 0.01). Using these results, we provide a simple relation between the maximum size of particle that can be delivered to the wind and the local mass-loss rate per unit area from the wind. This relation is independent of the physical origin of the wind and predicts typical sizes in the 0.01–$1\, \rm{\mu m}$ range for extreme-ultraviolet- or X-ray-driven winds. These values are a factor of ∼10 smaller than those obtained when considering only whether the wind is able to carry away the grains.

scholarly journals Simulation tests of selected gas flow parameters through combustion engine valves

2020 ◽  
Vol 183 (4) ◽  
pp. 21-28
Author(s):  
Monika Andrych-Zalewska
Keyword(s):  
Gas Flow ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Cross Sectional ◽  
Ic Engine ◽  
Flow Parameters ◽  
Sectional Plane ◽  
Concise Representation ◽  
Engine Valves

The article presents the numerical analysis of a single-cylinder gasoline engine with indirect injection and spark ignition. The goal is to recognize and analyze gas flow through inlet and outlet valves and channels. These data were obtained from the simulation of a four-cycle engine cycle without combustion of the fuel-air mixture. The simulation was carried out in ANSYS, using a dedicated IC Engine module. After the simulation, the result was analyzed on the cross-sectional plane of both the valves and the combustion chamber. This method provided the necessary and concise representation of the flow characteristics. Five separate stages are presented - two describing the different displacement of the valve for each inlet and exhaust stroke and one representing the phenomenon of overlapping. The type of flow, its speed and tendency to create turbulence are described

Successful Barrier Enhancement Application of Epoxy Based Resin for Multiple Casing to Casing Annuli Having Tight Injectivity - Case Study from Saudi Arabian Peninsula

2021 ◽  
Author(s):  
Abdulmalek Shamsan ◽  
Alejandro De la Cruz ◽  
Walmy Jimenez
Keyword(s):  
Epoxy Resin ◽  
Gas Flow ◽  
Resin System ◽  
Gas Leakage ◽  
Well Integrity ◽  
Epoxy Resin System ◽  
Modified Surface ◽  
Flow Through ◽  
Tailored Design

Abstract This study describes the approach used for enhancing the well integrity that was compromised with gas flow through a casing-casing annulus (CCA). Extremely tight injectivity at a CCA demands a solid free solution which not only can be injected but also resist high differential pressures to provide a long-term barrier in CCA. In this paper a successful leak remediation using an epoxy resin system helped the operator save a well and restart its production. Several pressure tests were conducted for identifying an extremely tight casing leak which was causing formation gas travelling to surface through the annulus. This issue required the customer to look for an efficient remedial solution to seal off the gas leakage and regain productivity. Due to the extremely low injectivity, a conventional cement squeeze or any solid laden particle-based squeeze approach was prone to fail. Alternatively, a tailored solid free epoxy resin system was placed in the annulus using an unconventional placement technique resulted in barrier enhancement and helped the operator place the well back into production. For a mature well flowing through 7 × 9 5/8‑in. and 9 5/8 × 13 3/8‑in., a tailored epoxy-based resin system formulation was placed in the well bore with modified surface operations procedures which helped in eliminating current annular pressure to regain well integrity and production. Remedial operations were performed from the surface by squeezing to seal off the gas coming from the annulus. A Tailored design derived from rigorous lab testing and perfect field execution resulted in CCA pressure remediation in a single attempt of the treatment injection, proving that the concept of using a solids-free resin to enhance existing deteriorated barriers is a reliable method. This epoxy resin system helped the operator to regain the well integrity and production in the shortest time without expensive well intervention operations. Epoxy resin based systems have been identified as a novel solution to remediate barrier integrity for well construction and workover operations, hence such case histories with enhanced operations procedures are helpful in increasing awareness of the benefits that can be attained in challenging high-pressure, low-injectivity environments, and can improve well economics.

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