By-pass transition of flat plate boundary layers on the surfaces near the limit of admissible roughness

Jonáš, Pavel; Hladík, O.; Mazur, Oton; Uruba, Václav

doi:10.1088/1742-6596/318/3/032030

Cited by 9 publications

(6 citation statements)

References 38 publications

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“…Based on the previous literature, the smooth metal surface has normally roughness of about 3.18 μm [ 22 ]. In high Reynolds number applications, surface roughness effect is used to increase the speed of transition from laminar-turbulent and delay flow separation [ 23 ]. Therefore, in order to reduce flow reversal and flow recirculation, roughness of height 50 to 200 μm has been applied.…”

Section: Baseline Compressor Specificationsmentioning

confidence: 99%

Centrifugal Compressor Stall Control by the Application of Engineered Surface Roughness on Diffuser Shroud Using Numerical Simulations

et al. 2021

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Downsizing in engine size is pushing the automotive industry to operate compressors at low mass flow rate. However, the operation of turbocharger centrifugal compressor at low mass flow rate leads to fluid flow instabilities such as stall. To reduce flow instability, surface roughness is employed as a passive flow control method. This paper evaluates the effect of surface roughness on a turbocharger centrifugal compressor performance. A realistic validation of SRV2-O compressor stage designed and developed by German Aerospace Center (DLR) is achieved from comparison with the experimental data. In the first part, numerical simulations have been performed from stall to choke to study the overall performance variation at design conditions: 2.55 kg/s mass flow rate and rotational speed of 50,000 rpm. In second part, surface roughness of magnitude range 0–200 μm has been applied on the diffuser shroud to control flow instability. It was found that completely rough regime showed effective quantitative results in controlling stall phenomena, which results in increases of operating range from 16% to 18% and stall margin from 5.62% to 7.98%. Surface roughness as a passive flow control method to reduce flow instability in the diffuser section is the novelty of this research. Keeping in view the effects of surface roughness, it will help the turbocharger manufacturers to reduce the flow instabilities in the compressor with ease and improve the overall performance.

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Section: Baseline Compressor Specificationsmentioning

confidence: 99%

Centrifugal Compressor Stall Control by the Application of Engineered Surface Roughness on Diffuser Shroud Using Numerical Simulations

et al. 2021

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“…Tu    (8) proposed by Mayle [4]. The effect of wall roughness on the transition onset was expressed by the correlation   (9) However experimental data of Jonáš et al [20] and Pinson and Wang [21] show that the wall roughness influences the transition even for k s +  5. Therefore a modification of the correlation according to Boyle and Stripf [6] was proposed in the form…”

Section: Rementioning

confidence: 99%

Modification of the Algebraic Transition Model for Wall Roughness Effect Including a Rough Strip

Straka¹,

Příhoda²

2020

Topical Problems of Fluid Mechanics 2020

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The contribution deals with the simulation of the laminar/turbulent transition on a rough wall. The algebraic transition model taking into account wall roughness according to Straka and Příhoda [8] was further extended for the effect of short rough strip near the leading edge. The proposed correlation was tested by means of incompressible flow over a flat plate covered by sand paper and around the NACA 0012 airfoil with a rough strip near the leading edge. The agreement with experiments is appropriate nevertheless the applicability of the correlation is limited due to the lack of relevant experimental results.

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“…The more convenient parameter is the ratio k s /θ t introduced by Mayle [11]. Provided that the Blasius boundary layer exists in the laminar part of the boundary layer, the non-dimensional equivalent sandgrain roughness can be correlated to the ratio Nevertheless, results of experimental investigation of the transition on a rough flat plate with sand paper carried out by Pinson and Wang [17] and Jonáš et al [18] show that the wall roughness influences the transition onset for values k s + < 5. Therefore, the transition correlation of Boyle and Stripf [2] was modified to the form…”

Section: Modelling Of Wall Roughness Effectmentioning

confidence: 99%

Extension of the algebraic transition model for the wall roughness effect

Straka

Příhoda

2016

EPJ Web of Conferences

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The contribution deals with the simulation of the laminar/turbulent transition taking into account the effect of wall roughness. The correlation for the transition onset proposed by Straka and PĜíhoda [1] was modified for the effect of the wall roughness using the correlation according to Boyle and Stripf [2]. This correlation derived for the wall roughness formed by regularly distributed truncated cones was modified for flows over the distributed wall roughness. The algebraic transition model proposed by Straka and PĜíhoda [1] with the modified relation for the transition onset was verified by means of the incompressible flat-plate boundary-layer and the compressible flow through the turbine blade cascade with rough blades. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits distribution, and reproduction in any medium, provided the original work is properly cited.

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By-pass transition of flat plate boundary layers on the surfaces near the limit of admissible roughness

Cited by 9 publications

References 38 publications

Centrifugal Compressor Stall Control by the Application of Engineered Surface Roughness on Diffuser Shroud Using Numerical Simulations

Centrifugal Compressor Stall Control by the Application of Engineered Surface Roughness on Diffuser Shroud Using Numerical Simulations

Modification of the Algebraic Transition Model for Wall Roughness Effect Including a Rough Strip

Extension of the algebraic transition model for the wall roughness effect

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