Investigations on the heat transfer within intake and exhaust valves at various engine speeds

Cerdoun, Mahfoudh; Khalfallah, Smail; Beniaiche, Ahmed; Carcasci, Carlo

doi:10.1016/j.ijheatmasstransfer.2019.119005

Cited by 23 publications

(17 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To cover this insufficiency, the present paper proposes to establish a FEM that considers the thermo-mechanical behaviour of an exhaust valve. It provides further results concerning the exhaust valve of the thermos-mechanical behaviour in the same exhaust valves studied by Cerdoun et al [14][15][16][17] Consequently, the main contribution of the present paper can be listed as follows:…”

Section: Introductionmentioning

confidence: 52%

“…After that, the same authors performed the previous model by introducing the effect of lubrication and the contact resistance. The tribology at the seat and at the guide, the flow regime within the exhaust port and heat transfer at the seat of different valve lift was all considered by Cerdoun et al 15,16 They also concluded that, the boundary conditions implemented as an average of HTC and adiabatic wall temperature (AWT), underestimate the temperature, whereas cyclic boundary condition required more run time to reach a steady state. Recently, Cerdoun et al 17 focused on the heat transfer within exhaust valves by considering the actual boundary conditions provided by an internal combustion engine at different loads and speeds.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermo-mechanical stress analysis within a steel exhaust valve of an internal combustion engine

Fersaoui

Cerdoun

May

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part C:

Self Cite

View full text Add to dashboard Cite

The valves of an internal combustion engine play an essential role in the automobiles and their surroundings significantly affect their thermo-mechanical behavior. The work aims to assess numerically the effect of the real thermo-mechanical boundary conditions on the valves by considering the actual complex surrounding. For this purpose, we have subdivided the valve into seven adequate zones. We have evaluated the average values of the transient heat transfer coefficient, the adiabatic wall temperature and the mechanical load at each subdivision are during the opening and the closing periods. A transient Finite Element Model under ANSYS APDL software is developed and simulations are carried out until reaching the steady state. The temperature distribution and the thermal stresses at each valve position is obtained and then analyzed. The main findings show that the stress intensity distribution is developed in the zones labelled stem guide port and seat local of large temperature gradients, which causes high thermal stresses responsible of cracks or thermal fatigue damage. In addition, knowing the temperature map, the thermal gradient and stress under actual conditions will surely help manufacturers to better design exhaust valve, avoid early failure and enhance the durability of valves.

show abstract

Section: Introductionmentioning

confidence: 52%

Section: Introductionmentioning

confidence: 99%

Thermo-mechanical stress analysis within a steel exhaust valve of an internal combustion engine

Fersaoui

Cerdoun

May

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part C:

Self Cite

View full text Add to dashboard Cite

show abstract

“…The temperature distribution is discussed in [23][24][25][26][27]. However, the boundary conditions being complex within the engine, digital models only allow access to orders of magnitude.…”

Section: Problems: Industrial Point Of Viewmentioning

confidence: 99%

Valve-seat components in a diesel engine: a tribological approach to limit wear

Crozet

Berthier

Saulot

et al. 2021

Mechanics & Industry

View full text Add to dashboard Cite

Within diesel engines, the valve-seat contact is one of the few non-lubricated contacts which is subjected to significant degradation. This degradation is put in evidence by material removal at the intake valve. The material pull out is promoted by the replication of combustion cycles (500 million) and severe operating conditions (pressure 18 MPa). The wear can lead to gas leakage and engine failure. The target of this work was to identify the main parameters affecting this wear. Our approach was based on the tribological triplet and material flows within the contact involving both numerical and experimental approaches. A dynamic model and a valvetrain test bench showed that the wear flows could be activated by the architecture of the valve opening system. Consequently, the limitation of these flows can be obtained by controlling the “global” geometry of the system and therefore without modifying the properties of the materials. In the same way, a finite element model of the local response of the seat-valve contact highlighted the impact of the “local” geometry of the contact. The change of this geometry is a lever to limit the shearing forces which reduces the tearing of the particles and therefore wear. Finally, tests carried out on the engine and on a specifically adapted test bench completed the understanding of degradation mechanisms (source flow, wear flow, etc.). Morphological interpretations of worn surfaces in terms of material flows allowed the understanding of the build-up stages of a protective layer. One solution to promote this internal flow is the use of pollutants from combustion. For example, the burned oil in contact, which is a priori harmful, becomes an opportunity here. In addition, un-burned hydrocarbons from the combustion of biodiesel help to protect the contact.

show abstract

“…One of the applied aspects in this area of research is the RICE exhaust system. New data on the gas dynamics and heat transfer of unstable processes in the exhaust system can be useful for refining valve strength calculation methods [16], improving the environmental performance of the engine [17], reducing exhaust noise [18], creating systems for the conversion of the thermal energy of exhaust gases [19,20] and updating the design of exhaust systems [21,22].…”

Section: Introductionmentioning

confidence: 99%

Thermal-mechanical characteristics of stationary and pulsating gas-flows in a gas-dynamic system: In relation the exhaust system of an engine

Plotnikov

2022

Therm sci

View full text Add to dashboard Cite

It is a relevant objective in thermal physics and in building reciprocating internal combustion engines (RICE) to obtain new information about the thermal-mechanical characteristics of both stationary and pulsating gas flows in a complex gas-dynamic system. The article discusses the physical features of the gas dynamics and heat transfer of flows along the length of a gas-dynamic system typical for RICE exhaust systems. Both an experimental set-up and experimental techniques are described. An indirect method for determining the local heat transfer coefficient of gas flows in pipelines with a constant temperature hot-wire anemometer is proposed. The regularities of changes in the instantaneous values of the flow rate and the local heat transfer coefficient in time for stationary and pulsating gas flows in different elements of the gas-dynamic system are obtained. The regularities of the change in the turbulence number of stationary and pulsating gas flows along the length of RICE gas-dynamic systems are established (it is shown that the turbulence number for a pulsating gas flow is 1.3-2.1 times higher than for a stationary flow). The regularities of changes in the heat transfer coefficient along the length of the engine?s gas-dynamic system for stationary and pulsating gas flows were identified (it was established that the heat transfer coefficient for a stationary flow is 1.05-1.4 times higher than for a pulsating flow). Empirical equations are obtained to determine the turbulence number and heat transfer coefficient along the length of the gas-dynamic system.

show abstract

Investigations on the heat transfer within intake and exhaust valves at various engine speeds

Cited by 23 publications

References 27 publications

Thermo-mechanical stress analysis within a steel exhaust valve of an internal combustion engine

Thermo-mechanical stress analysis within a steel exhaust valve of an internal combustion engine

Valve-seat components in a diesel engine: a tribological approach to limit wear

Thermal-mechanical characteristics of stationary and pulsating gas-flows in a gas-dynamic system: In relation the exhaust system of an engine

Contact Info

Product

Resources

About