Integration of Unsteady Effects in the Turbocharger Design Process

2012 ◽  
Author(s):  
Apostolos Pesiridis ◽  
Sotirios Lioutas ◽  
Ricardo F. Martinez-Botas
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Weighted Averaging ◽  
Initial Attempt ◽  
Lower Efficiency ◽  
Turbocharged Diesel Engine ◽  
One Dimensional ◽  
Flow Through ◽  
Unsteady Effects ◽  
Selection Of

Turbocharger development is based on performance maps arising through steady state measurements, although the flow through the engine-turbocharger system is highly unsteady. This paper investigates the potential for integrating the effects from unsteady flow in the turbine map, in order to enhance the performance of the ICE-turbocharger system. It is, also, an initial attempt to set the framework for more accurate one-dimensional turbine simulations in order to improve the selection of turbocharger components and their matching with the ICE. The development of ‘equivalent unsteady’ maps is presented, based on energy-weighted averaging of available, unsteady, experimental data and its deviations from quasi-steady performance. The maps are subsequently used for a one dimensional (1D) simulation of a turbocharged diesel engine running at 800 RPM and 1600 RPM. A comparative assessment with results from simulations using a conventional steady-state map has shown important differences in turbine parameters (up to 12% lower efficiency and 6% lower mass flow parameter) but minor differences, of less than 1% in terms of engine performance and fuel consumption.

Selection of one-dimensional sedimentation: models for on-line use

1995 ◽  
Vol 31 (2) ◽  
pp. 193-204 ◽  
Author(s):  
Koen Grijspeerdt ◽  
Peter Vanrolleghem ◽  
Willy Verstraete
Keyword(s):  
Steady State ◽  
Selection Criteria ◽  
Data Sets ◽  
Concentration Profiles ◽  
A Posteriori ◽  
One Dimensional ◽  
On Line ◽  
Dynamic Concentration ◽  
Selection Of ◽  
Modelling Task

A comparative study of several recently proposed one-dimensional sedimentation models has been made. This has been achieved by fitting these models to steady-state and dynamic concentration profiles obtained in a down-scaled secondary decanter. The models were evaluated with several a posteriori model selection criteria. Since the purpose of the modelling task is to do on-line simulations, the calculation time was used as one of the selection criteria. Finally, the practical identifiability of the models for the available data sets was also investigated. It could be concluded that the model of Takács et al. (1991) gave the most reliable results.

Influence of Unsteady Effects on Air Venting in Pressure Die Casting

2001 ◽  
Vol 123 (4) ◽  
pp. 884-892 ◽  
Author(s):  
J. Herna´ndez ◽  
J. Lo´pez ◽  
F. Faura
Keyword(s):  
Method Of Characteristics ◽  
Die Casting ◽  
Operating Conditions ◽  
Filling Process ◽  
Air Mass ◽  
One Dimensional ◽  
Trapped Air ◽  
Unsteady Effects ◽  
Pressure Die Casting ◽  
Selection Of

The influence of unsteady effects on the evacuation of air through vents in pressure die casting processes is analyzed. A model is proposed which considers the air flow as one-dimensional and adiabatic, and which retains friction effects. Venting conditions for wide ranges of the relevant dimensionless parameters are analyzed for both atmospheric and vacuum venting systems. The model is solved numerically using the method of characteristics and its results are compared with those obtained for quasi-steady models. It is shown that wide ranges of operating conditions can exist in practical situations, for which unsteady effects, neglected in previous models, are important and must be taken into account to determine the air mass entrapped at the end of the filling process. The selection of parameters which will reduce the amount of trapped air and thus porosity in manufactured parts is also discussed.

The Effect of Coatings on the Steady-State and Short Time Constriction Resistance for an Arbitrary Axisymmetric Flux

1985 ◽  
Vol 107 (1) ◽  
pp. 33-38 ◽  
Author(s):  
J. R. Dryden ◽  
M. M. Yovanovich ◽  
A. S. Deakin
Keyword(s):  
Thermal Properties ◽  
Steady State ◽  
Heat Flow ◽  
Contact Spot ◽  
One Dimensional ◽  
Constriction Resistance ◽  
Transient Heat Flow ◽  
Flow Through ◽  
Short Time ◽  
Short Times

The effect of a coating upon the short-time and steady-state constriction resistance is analyzed for an arbitrary axisymmetric contact spot flux. At very short times the expression obtained for R is identical to the expression for one-dimensional transient heat flow through a two-layer wall. At steady-state, the results of the analysis predict that the effect of the coating are mainly dependent on the relative thermal properties of the coating and substrate. The limiting cases, where the coating thickness approaches either zero or infinity, are discussed.

scholarly journals Performance Benefits for Wave Rotor-Topped Gas Turbine Engines

1996 ◽  
Author(s):  
Scott M. Jones ◽  
Gerard E. Welch
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Cycle Performance ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Turbine Engine ◽  
One Dimensional

The benefits of wave rotor-topping in turboshaft engines, subsonic high-bypass turbofan engines, auxiliary power units, and ground power units are evaluated. The thermodynamic cycle performance is modeled using a one-dimensional steady-state code; wave rotor performance is modeled using one-dimensional design/analysis codes. Design and off-design engine performance is calculated for baseline engines and wave rotor-topped engines, where the wave rotor acts as a high pressure spool. The wave rotor-enhanced engines are shown to have benefits in specific power and specific fuel flow over the baseline engines without increasing turbine inlet temperature. The off-design steady-state behavior of a wave rotor-topped engine is shown to be similar to a conventional engine. Mission studies are performed to quantify aircraft performance benefits for various wave rotor cycle and weight parameters. Gas turbine engine cycles most likely to benefit from wave rotor-topping are identified. Issues of practical integration and the corresponding technical challenges with various engine types are discussed.

Thermal Conductivity for Mixture of Rice Husk Fiber and Gypsum

2016 ◽  
Vol 819 ◽  
pp. 69-73 ◽  
Author(s):  
Mohamad Nor Musa ◽  
Mohamed Fikhri Abdul Aziz
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Rice Husk ◽  
Single Specimen ◽  
Hot Plate ◽  
Plate Method ◽  
One Dimensional ◽  
State Technique ◽  
Application Potential ◽  
Flow Through

This project is conducted with aim to determine the thermal conductivity for mixture of rice husk fiber and gypsum. The thermal conductivity value for 100% gypsum is also determined in this project for comparison purpose. The experiment used the Guarded Hot Plate Method, single specimen apparatus. This method is based on one-dimensional heat flow through conduction and steady state technique. Four samples have been tested which are 100% gypsum with a mass of 1kg for sample 1, a mixture of 0.1kg of rice husk fiber and 1kg gypsum for sample 2, mixture of 0.2kg of rice husk fiber and 1kg gypsum for sample 3 and a mixture of 0.3kg of rice husk fiber and 1kg gypsum for sample 4. From the data of the experiment that have been carried out, the value of thermal conductivity is decreasing with the increasing of rice husk fiber in the sample. The value of thermal conductivity is 0.772W/mK for sample 1, 0.7574 W/mK for sample 2, 0.7469W/mK for sample 3 and 0.7368W/mK for sample 4. The rice husk fiber is a bio-waste material and the mixture of rice husk fiber and gypsum will add value to the material as gypsum are widely used in construction field such as for plaster ingredient and ceiling finishing because it is a good insulator. The mixture of rice husk fiber and gypsum improve the 100% gypsum thermal conductivity and therefore the mixing of these two materials should have bright application potential.

Sign in / Sign up

Export Citation Format

Share Document