In-Cylinder Heat Transfer Model for Diesel Engine Based on Improved Woschni Correlation

2014 ◽  
Vol 538 ◽  
pp. 175-178
Author(s):  
Xiao Ri Liu ◽  
Guo Xiang Li ◽  
Yu Ping Hu ◽  
Shu Zhan Bai ◽  
Kang Yao Deng
Keyword(s):  
Heat Transfer ◽  
Cfd Simulation ◽  
Transient Flow ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Three Dimension ◽  
Characteristic Parameters ◽  
Flow And Heat Transfer ◽  
Dimension Characteristic

Based on the Woschni correlation, a three dimensional in-cylinder heat transfer model is proposed, which develops Woschni correlation from zero dimension to three dimension. Characteristic parameters are proposed as transient flow and heat transfer parameters from in-cylinder CFD simulation, with further consideration of the influence of thermal conductivity, viscosity and Prandtl number. According to test data, the new correlation can be regressed. The new model costs little more calculation time, and it can satisfy the engineering demand.

Numerical Study on Coupled Heat Transfer of Thrust Chamber with Raised Structure

2012 ◽  
Vol 516-517 ◽  
pp. 107-110
Author(s):  
Tao Nie ◽  
Wei Qiang Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Axial Direction ◽  
Heat Transfer Model ◽  
Chamber Wall ◽  
Transfer Model ◽  
Thrust Chamber ◽  
Coupled Heat Transfer ◽  
Flow And Heat Transfer

By the use of the map of the thermal resistance among volume cells, we establish a coupled heat transfer model of the hot gas, chamber wall and coolant. A reduced one-dimensional model was employed for the coolant flow and heat transfer, and three dimensional heat transfer model was used to calculate the coupling heat transfer through the wall, considering heat transfer at circumferential direction, axial direction and radial direction. Based on the study the mechanism of the cooling structure heat transfer, the computing model was employed and achieved the rule of heat flux and temperature of gas wall. Simultaneously, influence of different cooling structure was performed. The results indicated that the cooling structure with raised structure could better reduce the temperature of the chamber wall.

Transient Three-Dimensional Heat Transfer Model of a Solar Thermochemical Reactor for H2O and CO2 Splitting via Nonstoichiometric Ceria Redox Cycling

2013 ◽  
Author(s):  
Justin Lapp ◽  
Wojciech Lipiński
Keyword(s):  
Heat Transfer ◽  
Heat Recovery ◽  
Fuel Efficiency ◽  
Three Dimensional ◽  
Reactor Design ◽  
Heat Transfer Model ◽  
Heat Fluxes ◽  
Transfer Model ◽  
Rotating Cylinders ◽  
Solar Receiver

A transient heat transfer model is developed for a solar reactor prototype for H2O and CO2 splitting via two-step non-stoichiometric ceria cycling. Counter-rotating cylinders of reactive and inert materials cycling between high and low temperature zones permit continuous operation and heat recovery. To guide the reactor design a transient three-dimensional heat transfer model is developed based on transient energy conservation, accounting for conduction, convection, radiation, and chemical reactions. The model domain includes the rotating cylinders, a solar receiver cavity, and insulated reactor body. Radiative heat transfer is analyzed using a combination of the Monte Carlo method, Rosseland diffusion approximation, and the net radiation method. Quasi-steady state distributions of temperatures, heat fluxes, and the non-stoichiometric coefficient are reported. Ceria cycles between temperatures of 1708 K and 1376 K. A heat recovery effectiveness of 28% and solar-to-fuel efficiency of 5.2% are predicted for an unoptimized reactor design.

scholarly journals Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

2018 ◽  
Vol 21 (8) ◽  
pp. 1286-1297 ◽  
Author(s):  
Antonio Gil ◽  
Andrés Omar Tiseira ◽  
Luis Miguel García-Cuevas ◽  
Tatiana Rodríguez Usaquén ◽  
Guillaume Mijotte
Keyword(s):  
Heat Transfer ◽  
Coke Formation ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Thermal Design ◽  
Working Fluid ◽  
Transfer Model ◽  
Lumped Model ◽  
Bearing System

Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine-operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieved due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available fall outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This article presents a fast three-dimensional heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine-operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads to oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures. Model validation is illustrated, and finally, the main results are discussed.

scholarly journals Group Invariant Solutions for Flow and Heat Transfer of Power-Law Nanofluid in a Porous Medium

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Saba Javaid ◽  
Asim Aziz
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Power Law ◽  
Internal Heat ◽  
Shear Thickening ◽  
Internal Heat Source ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Flow And Heat Transfer ◽  
Power Law Nanofluid

The present work covers the flow and heat transfer model for the power-law nanofluid in the presence of a porous medium over the penetrable plate. The flow is caused by the impulsive movement of the plate embedded in Darcy’s type porous medium. The flow and heat transfer model has been examined with the effect of linear thermal radiation and the internal heat source or sink in the flow regime. The Rosseland approximation is utilized for the optically thick nanofluid. To form the closed-form solutions for the governing partial differential equations of conservation of mass, momentum, and energy, the Lie symmetry analysis is used to get the reductions of governing equations and to find the group invariants. These invariants are then utilized to obtain the exact solution for all three cases, i.e., shear thinning fluid, Newtonian fluid, and shear thickening fluid. In the end, all solutions are plotted for the cu -water nanofluid and discussed briefly for the different emerging flow and heat transfer parameters.

Development of a Three-Dimensional Heat Transfer Model for Continuous Annealing of Steel Strip

2011 ◽  
Vol 51 (4) ◽  
pp. 1790-1795 ◽  
Author(s):  
N. Depree ◽  
M. P. Taylor ◽  
J. J. J. Chen ◽  
J. Sneyd ◽  
S. Taylor ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Steel Strip ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Continuous Annealing ◽  
Transfer Model
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