Engine permeability, which is commonly knownto exert a strong influence on engine performances, isusually experimentally addressed by means of thedefinition of a global parameter, the steady dischargecoefficient. Nevertheless, the use of such a parameter todescribe valve-port assembly behaviour appearssometimes to be insufficient to determine portfluidynamic behaviour, due to the simultaneousconcurrency of complex mechanisms, such as meanflow distortions and boundary layer detachments. CFDsimulation appears therefore to be a fundamental tool tofully understand port fluidynamic behaviour.In the present paper, two engine intake portassemblies are investigated by using the STAR-CD CFDcode, showing a strongly different behaviour from thepoint of view of secondary detached flows generationacross the valve. Flow separation in the valve seatregion reveals to be detrimental on engine steadybreathing performances, since the subsequentrecirculation region strongly limits the valve curtainusage and forces the mean flow to crash against thevalve. In order to reduce the growth of secondarydetached flows upstream of the valve seat, the detachfavourableport is equipped with a boundary layer controlpneumatic device, which proves to be capable of nearlyeliminating flow separation in the valve region. Thissolution is finally compared to the non-detaching design,showing a non negligible benefit in terms of dischargecoefficient, and therefore engine permeability. Since theevaluation of the steady-flow discharge coefficient andflow patterns of ICE port assembly is strongly sensitiveto the capability of the turbulence sub-models incapturing the boundary layer dynamics, cubic low-Reynolds k-ε model is used for simulations.
Development and validation of a boundary layer control system to increase intake port steady permeability / Fontanesi, Stefano. - In: SAE TECHNICAL PAPER. - ISSN 0148-7191. - ELETTRONICO. - Non presente:(2004), pp. 1-18. (Intervento presentato al convegno SAE 2004 World Congress tenutosi a Detroit, MI, usa nel Aprile 2004) [10.4271/2004-01-0111].
Development and validation of a boundary layer control system to increase intake port steady permeability
FONTANESI, Stefano
2004
Abstract
Engine permeability, which is commonly knownto exert a strong influence on engine performances, isusually experimentally addressed by means of thedefinition of a global parameter, the steady dischargecoefficient. Nevertheless, the use of such a parameter todescribe valve-port assembly behaviour appearssometimes to be insufficient to determine portfluidynamic behaviour, due to the simultaneousconcurrency of complex mechanisms, such as meanflow distortions and boundary layer detachments. CFDsimulation appears therefore to be a fundamental tool tofully understand port fluidynamic behaviour.In the present paper, two engine intake portassemblies are investigated by using the STAR-CD CFDcode, showing a strongly different behaviour from thepoint of view of secondary detached flows generationacross the valve. Flow separation in the valve seatregion reveals to be detrimental on engine steadybreathing performances, since the subsequentrecirculation region strongly limits the valve curtainusage and forces the mean flow to crash against thevalve. In order to reduce the growth of secondarydetached flows upstream of the valve seat, the detachfavourableport is equipped with a boundary layer controlpneumatic device, which proves to be capable of nearlyeliminating flow separation in the valve region. Thissolution is finally compared to the non-detaching design,showing a non negligible benefit in terms of dischargecoefficient, and therefore engine permeability. Since theevaluation of the steady-flow discharge coefficient andflow patterns of ICE port assembly is strongly sensitiveto the capability of the turbulence sub-models incapturing the boundary layer dynamics, cubic low-Reynolds k-ε model is used for simulations.File | Dimensione | Formato | |
---|---|---|---|
2004-01-0111.pdf
Accesso riservato
Descrizione: Articolo completo
Tipologia:
Versione pubblicata dall'editore
Dimensione
748.82 kB
Formato
Adobe PDF
|
748.82 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris