Effect of Circuit Geometry on Steady Flow Performance of an Automotive Turbocharger Compressor

Marelli, Silvia; Carraro, C.; Moggia, Simone; Capobianco, Massimo

doi:10.1016/j.egypro.2016.11.080

Cited by 5 publications

(3 citation statements)

References 18 publications

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“…The inflow is assumed to be inhomogeneous for both configurations; however, increased map width could be detected. Similar results were investigated by Galindo et al [5][6][7], Hou et al [8], Elkamel [9], Marelli et al [10] and Serrano [11]. In contrast to Kerres' results, Bayomi [12] stated that map width enhancement is gained by assembling flow straighteners upstream of the compressor, providing a more homogeneous inflow.…”

Section: Introductionsupporting

confidence: 77%

Surge Limit Prediction for Automotive Air-Charged Systems

Bühler

Leichtfuß

Schiffer

et al. 2019

IJTPP

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Compressor surge has been investigated and predicted since the early days of turbomachinery research. Experimental testing of turbomachinery applications is still needed to determine whether stable compressor operation is possible in the expected application regime. Measuring compressor maps and operating ranges on hot gas test stands is common. The test benches are designed and optimized to ensure ideal inflow and outflow conditions as well as low measurement uncertainty. Compressor maps are used to match turbocharger and application. However, a shift in surge limit, caused by the piping system or application, can only be adequately addressed with full engine tests. Ideal measurements use the corresponding piston engine in the charged-air system. This can only take place in the development process, when surge detection is unfavorable from an economic perspective. The surge model for turbochargers presented here is an extension of the Greitzer’s surge model, which considers the effect of inlet throttling. Application components, such as air filters, pipe elbows and flow straighteners, reduce pressure in front of the compressor and flow conditions might differ from those in laboratory testing. Experimental results gathered from the hot gas test stand at TU Darmstadt indicate strong variation in surge limit, influenced by inlet throttling. An extension to the surge model is developed to explain the observed phenomena. The model was validated using extensive experimental variations and matches the experienced surge limit shift. Additional measurements with a piston engine downstream of the turbocharger demonstrated the validity of the surge model. The results also show that surge is a system-dependent phenomenon, influenced by compressor aerodynamics and boundary conditions.

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Section: Introductionsupporting

confidence: 77%

Surge Limit Prediction for Automotive Air-Charged Systems

Bühler

Leichtfuß

Schiffer

et al. 2019

IJTPP

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“…Surge has been studied for last three decades [2,3] to design systems to avoid its occurrence [4,5]. Many parameters affect the surge instability and especially geometry and operating conditions of the compressor but also downstream and upstream geometry circuit [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Turbocharger surge behavior for sudden valve closing downstream the compressor and effect of actuating variable nozzle turbine

Danlos

Podevin

Deligant

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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Surge is an unstable phenomenon appearing when a valve closing reduces the compressor flow rate. This phenomenon is avoided for automotive turbochargers by defining a surge margin during powertrain system design. This surge margin established with measurements in steady state testing regime limits the maximal engine torque at low levels of output. An active control of the compressor could reduce the surge margin and facilitate a transient compressor operation for a short time in surge zone. In this paper, an experimental study of the transient operation of a turbocharger compressor entering the surge zone is performed. Control of the turbocharger speed is sought to avoid unsteady operation using the variable geometry turbine (VGT) nozzle actuator. From a given stable operating point, surge is induced by reducing the opening of a valve located downstream of the compressor air circuit. The effect of reducing the speed of rotation by controlling the VGT valve is investigated, as this should lead to more stable compressor operation. The rotation speed of the turbocharger is controlled to avoid an unstable operating point using servo-actuator of variable geometry turbine. From a stable operating point, the surge appearance is caused by closing a butterfly valve downstream the air circuit of the compressor. The effect on the compressor rotation speed when the opening of variable geometry turbocharger valve is modified is studied. Measurements have been conducted for different control profiles of the VGT valve placed downstream the compressor. This article presents the means used to carry out these tests as well as the results of the measurements of the instantaneous signals of pressure, temperature, flow rate and rotation speed, allowing the analysis of the surge phenomenon.

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“…Pioneering experimental studies have been carried out on the influence of pulsating backpressure on the performance of centrifugal compressor in recent decade [5][6][7]. The pulsating backpressure is produced by a pulse generator which is installed downstream the compressor to simulate the intake valves.…”

Section: Introductionmentioning

confidence: 99%

Experimental study on performance of centrifugal compressor exposed to pulsating backpressure

Shu

Yang

Zhang

et al. 2019

Aerospace Science and Technology

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Pressure fluctuations in intake manifold of Internal Combustion Engine introduce a pulsating boundary condition to the centrifugal compressor. In this study, the performance of centrifugal compressor exposed to pulsating backpressure is experimentally investigated. Unsteady performance and surge characteristic of the compressor at different pulsating conditions are analyzed. Results show that instantaneous performance of the compressor forms a hysteresis loop encapsulating steady performance. A correlation of compressor unsteadiness with pulse frequency, magnitude, and local slope of the characteristic curve is obtained based on measurements. Cycle-average performance of the compressor is notably lower than that at constant conditions. Specifically, the averaged peak efficiency at pulsating condition drops 3%~7%. Fast Fourier Transformation method is applied to study surge characteristics at pulsating conditions. Results manifest that compressor surge is postponed remarkably by pulsating backpressure at all conditions. As the compressor approaches to small mass flow rate, flow fluctuations decay quickly and then increase dramatically when the surge happens, forming the variation with 'V-shape' for frequency domains. This phenomenon is resulted from the influence of the slope of characteristic curve on the filling-empty and compressor stability. Smaller slope produces less filling-empty and hence smaller size of the loop, but reduces the stability of compressing system and initiates surge.

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Effect of Circuit Geometry on Steady Flow Performance of an Automotive Turbocharger Compressor

Cited by 5 publications

References 18 publications

Surge Limit Prediction for Automotive Air-Charged Systems

Surge Limit Prediction for Automotive Air-Charged Systems

Turbocharger surge behavior for sudden valve closing downstream the compressor and effect of actuating variable nozzle turbine

Experimental study on performance of centrifugal compressor exposed to pulsating backpressure

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