Calculation of temperature profiles of high pressure electric arcs using the diffusion approximation for radiation transfer

1969 ◽  
Vol 9 (2) ◽  
pp. 207-236 ◽  
Author(s):  
J.J. Lowke ◽  
E.R. Capriotti
Keyword(s):  
High Pressure ◽  
Diffusion Approximation ◽  
Radiation Transfer ◽  
Temperature Profiles ◽  
Electric Arcs

scholarly journals A model of the injection moulding process

1995 ◽  
Vol 37 (1) ◽  
pp. 1-15 ◽  
Author(s):  
J. Whale ◽  
N. Fowkes ◽  
G. Hocking ◽  
D. Hill
Keyword(s):  
High Pressure ◽  
Steady State ◽  
Injection Moulding ◽  
Temperature Profiles ◽  
Average Pressure ◽  
Moulding Process ◽  
Injection Moulding Process ◽  
Steady State Model ◽  
The Relationship ◽  
Average Pressure Gradient

AbstractThis paper is concerned with the injection moulding process, in which hot molten plastic is injected under high pressure into a thin cold mould. Assuming that the velocity and temperature profiles across the mould maintain their shape, a simple steady state model to describe the behaviour of a Newtonian fluid during the filling stage is developed. Various phenomena of the process are examined, including the formation of a layer of solid plastic along the walls of the mould, and the relationship between the flux of liquid plastic through the mould and the average pressure gradient along the mould. In any given situation, it is shown that there is a range of pressures and injection temperatures which will give satisfactory results.

Hydrate Plug Movement by One-Sided Depressurization

2012 ◽  
Author(s):  
Marcelo Gonçalves ◽  
Ricardo Camargo ◽  
Angela O. Nieckele ◽  
Rafael Faraco ◽  
Claudio Veloso Barreto ◽  
...  
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Risk Evaluation ◽  
Pressure Variation ◽  
Temperature Profiles ◽  
Gas Composition ◽  
Offshore Production ◽  
Physical Representation ◽  
Hydrate Plug ◽  
Velocity Pressure

A new model that accurately predicts hydrate plug displacement during a one-sided depressurization is presented. This model is both simple to handle and rigorous in the physical representation of the phenomenon. It was implemented as a finite volume transient simulator capable of determining the flow field coupled with the plug displacement dynamics after its detachment. It takes into consideration velocity, pressure and temperature profiles across chambers upstream and downstream the plug at each instant of time, as well as pipe deformation due to pressure variations inside the chambers. Typical cases for deep offshore production are analyzed. The influence on the plug displacement of the gas composition, the temperature variation due to the heat loss to the environment and high pressure variation is addressed. Results show that, depending on the conditions, and after performing a careful risk evaluation, it may be safe to remediate hydrate plug by one-sided depressurization in a number of typical situations in offshore production scenario.

The Use of CFD for the Thermal Analysis of a High Pressure Compressor Rotor

2004 ◽  
Author(s):  
U. W. Ruedel ◽  
J. R. Turner
Keyword(s):  
Thermal Analysis ◽  
High Pressure ◽  
Temperature Distribution ◽  
Flow Field ◽  
Transient Temperature ◽  
Temperature Profiles ◽  
Cfd Analysis ◽  
Compressor Rotor ◽  
High Pressure Compressor ◽  
Pressure Compressor

The prediction of fatigue life of components inside aircraft engines depends on the reliable numerical modelling of the temperature distribution during a mission cycle as this gives rise to life limiting thermal stresses. The transient temperature distribution is usually measured during an engine test and is then used to validate the numerical model, which in turn produces the basis for calculating the thermal stress levels. This paper describes the thermal analysis of a High Pressure Compressor Rotor (HPCR) and how the use of a 3-D Computational Fluid Dynamic (CFD) analysis improved the quantitative agreement between the measured and the predicted temperature profiles. The highly complex three-dimensional flow field within the compressor rotor was modelled by exploiting symmetry conditions and using a standard k-ε turbulence model. Results of the tangential, axial and radial velocity components as well as locations of peaks in turbulence kinetic energy were predicted to help identify the flow field inside the forward cavity of the rotor. Two ways of predicting internal re-circulating rates to the rim area are proposed. Finally, plots of predicted metal temperature profiles before and after the CFD-analysis are presented.

Heat Transfer for the Film-Cooled Vane of a 1-1/2 Stage High-Pressure Transonic Turbine—Part I: Experimental Configuration and Data Review With Inlet Temperature Profile Effects

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Harika S. Kahveci ◽  
Charles W. Haldeman ◽  
Randall M. Mathison ◽  
Michael G. Dunn
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Inlet Temperature ◽  
Temperature Profiles ◽  
Turbine Stage ◽  
Suction Surface ◽  
Airfoil Surface ◽  
Pressure Surface ◽  
Cooling Flow ◽  
The Impact

This paper investigates the vane airfoil and inner endwall heat transfer for a full-scale turbine stage operating at design corrected conditions under the influence of different vane inlet temperature profiles and vane cooling flow rates. The turbine stage is a modern 3D design consisting of a cooled high-pressure vane, an un-cooled high-pressure rotor, and a low-pressure vane. Inlet temperature profiles (uniform, radial, and hot streaks) are created by a passive heat exchanger and can be made circumferentially uniform to within ±5% of the bulk average inlet temperature when desired. The high-pressure vane has full cooling coverage on both the airfoil surface and the inner and outer endwalls. Two circuits supply coolant to the vane, and a third circuit supplies coolant to the rotor purge cavity. All of the cooling circuits are independently controlled. Measurements are performed using double-sided heat-flux gauges located at four spans of the vane airfoil surface and throughout the inner endwall region. Analysis of the heat transfer measured for the uncooled downstream blade row has been reported previously. Part I of this paper describes the operating conditions and data reduction techniques utilized in this analysis, including a novel application of a traditional statistical method to assign confidence limits to measurements in the absence of repeat runs. The impact of Stanton number definition is discussed while analyzing inlet temperature profile shape effects. Comparison of the present data (Build 2) to the data obtained for an uncooled vane (Build 1) clearly illustrates the impact of the cooling flow and its relative effects on both the endwall and airfoils. Measurements obtained for the cooled hardware without cooling applied agree well with the solid airfoil for the airfoil pressure surface but not for the suction surface. Differences on the suction surface are due to flow being ingested on the pressure surface and reinjected on the suction surface when coolant is not supplied for Build 2. Part II of the paper continues this discussion by describing the influence of overall cooling level variation and the influence of the vane trailing edge cooling on the vane heat transfer measurements.

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