Uncertainties in power computations in a turbocharger test bench

A specific study of the uncertainties of turbine power output measured in turbocharger test benches is presented using the law of uncertainty propagation and the influence of the different terms that contribute to it is shown. Then, non-linear mixed integer mathematical programming algorithms used with the turbine power uncertainty expression become an essential tool to overcome the problem of selection new sensors to improve an existing test rig or to contribute to a new one. A method of optimisation is presented for two different scenarios: first, where the maximum cost is a constraint; second where the maximum uncertainty is a constraint and the total cost is minimised. When using a large transducers database, computational efforts may be reduced by solving the relaxed non-integer problem by means of sequential quadratic programming and then probing the ceilings and floors of the parameters to get an optimum approximation with low costs. A comparison between the linear uncertainty propagation model and Monte Carlo simulations is also presented, only showing benefits of the later method when computing high order statistical moments of the turbine power output probability distribution.This work has been partially supported by the Spanish Ministerio de Ciencia e Innovacion through Grant No. DPI2010-20891-C02-02 and by the Spanish Ministerio de Economia y Competitividad through Grant No. TRA2012-36954.Olmeda González, PC.; Tiseira Izaguirre, AO.; Dolz Ruiz, V.; García-Cuevas González, LM. (2015). Uncertainties in power computations in a turbocharger test bench. Measurement. 59:363-371. https://doi.org/10.1016/j.measurement.2014.09.055S3633715

Variable Geometry Turbocharger Technologies for Exhaust Energy Recovery and Boosting-A Review

As emissions regulations become increasingly demanding, higher power density engine (downsized/downspeeded and increasingly right-sized) requirements are driving the development of turbocharging systems. Variable geometry turbocharging (VGT) at its most basic level is the first step up from standard fixed geometry turbocharger systems. Currently, VGTs offer significant alternative options or complementarity vis-à-vis more advanced turbocharging options. This review details the range of prominent variable geometry technologies that are commercially available or openly under development, for both turbines and compressors and discusses the relative merits of each. Along with prominent diesel-engine boosting systems, attention is given to the control schemes employed and the actuation systems required to operate variable geometry devices, and the specific challenges associated with turbines designed for gasoline engines

Radial inflow turbine : performance characteristics under steady and unsteady flow.

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Radial inflow turbine Performance characteristics under steady and unsteady flow

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