Modeling of Two-Phase Evaporative Heat Transfer in Three-Dimensional Multicavity High Performance Microprocessor Chip Stacks

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Yassir Madhour ◽  
Brian P. d'Entremont ◽  
Jackson Braz Marcinichen ◽  
Bruno Michel ◽  
John Richard Thome
Keyword(s):  
Integrated Circuit ◽  
Hot Spots ◽  
High Performance ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Simulation Method ◽  
Heat Fluxes ◽  
Signal Delay ◽  
Two Phase ◽  
Signal Delay Time

Three-dimensional (3D) stacking of integrated-circuit (IC) dies increases system density and package functionality by vertically integrating two or more dies with area-array through-silicon-vias (TSVs). This reduces the length of global interconnects and the signal delay time and allows improvements in energy efficiency. However, the accumulation of heat fluxes and thermal interface resistances is a major limitation of vertically integrated packages. Scalable cooling solutions, such as two-phase interlayer cooling, will be required to extend 3D stacks beyond the most modest numbers of dies. This paper introduces a realistic 3D chip stack along with a simulation method for the heat spreading and flow distribution among the channels of the evaporators. The model includes the significant sensitivity of each channel's friction factor to vapor quality, and hence mass flow to heat flux, which characterizes parallel two-phase flows. Simulation cases explore various placements of hot spots within the stack and effects which are unique to two-phase interlayer cooling. The results show that the effect of hot spots on individual dies can be mitigated by strong interlayer heat conduction if the relative position of the hot spots is selected carefully to result in a heat load and flow which are well balanced laterally.

3D Stacks of Microprocessors and Memories With Backside Two-Phase Multi-Microchannel Cooler

2013 ◽  
Author(s):  
Jackson B. Marcinichen ◽  
John R. Thome
Keyword(s):  
Integrated Circuit ◽  
High Performance ◽  
Flow Distribution ◽  
Two Phase ◽  
Hydrodynamic Simulations ◽  
3D Ics ◽  
Technological Advances ◽  
High Level ◽  
Transfer Of Information ◽  
High Performance Computers

For the next generation of high performance computers, the new challenges are to shorten the distance for transporting data (to accelerate the transfer of information) between multi-microprocessors and memories, and to cool these electronic components despite the increased heat flux that results from increased transistor density. Recent technological advances show a tendency for the development of 3D integrated circuit stacked architectures with interlayer cooling (multi-microchannels in the silicon layers). However, huge challenges exist in such design/concept, i.e. flow distribution to hundreds microchannels distributed in the different interlayers, thermo-hydrodynamic and geometrical limitations, manufacturing etc. 3D-ICs with interlayer cooling are still about a decade away, so a viable shorter term goal is 3D stacks with backside cooling, taking advantage of Si layers now able to be thineer down to only 50 μm thickness. Thus, the present work presents thermo-hydrodynamic simulations for 3D stacks considering only a backside cooler, which simplifies considerably the assembly and guarantees a high level of reliability. In summary, the results showed that this concept is thermally feasible and potentially that interlayer microchannels (between stacks) will not be necessary.

Development of High Performance Steam Separator System (1) Design Procedure of Swirler by Three-dimensional Two-phase Flow Simulation Method

2003 ◽  
Vol 2003.3 (0) ◽  
pp. 161-162
Author(s):  
Hiroshi IKEDA ◽  
Takeshi SHIMIZU ◽  
Tadashi NARABAYASHI ◽  
Koji NISHIDA ◽  
Toshihiko FUKUDA ◽  
...  
Keyword(s):  
High Performance ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Design Procedure ◽  
Flow Simulation ◽  
Simulation Method ◽  
Phase Flow ◽  
Two Phase ◽  
System 1 ◽  
Steam Separator

scholarly journals Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Force ◽  
Rotor Blade ◽  
Flow Direction ◽  
Three Dimensional ◽  
Simulation Method ◽  
Two Phase ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Flow Field Characteristics

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.

Age-Related Differences in Throwing Techniques Used by the Catcher in Baseball

1994 ◽  
Vol 6 (3) ◽  
pp. 225-235 ◽  
Author(s):  
Shinji Sakurai ◽  
Bruce Elliott ◽  
J. Robert Grove
Keyword(s):  
High Speed ◽  
High Performance ◽  
Age Groups ◽  
Three Dimensional ◽  
Transformation Method ◽  
High Speed Photography ◽  
Two Phase ◽  
Ball Speed ◽  
Age Related ◽  
Release Speed

Three-dimensional (3-D) high speed photography was used to record the overarm throwing actions of five open-age, four 18-year-old, six 16-year- old, and six 14-year-old high-performance baseball catchers. The direct linear transformation method was used for 3-D space reconstruction from 2-D images of the catchers throwing from home plate to second base recorded using two phase-locked cameras operating at a nominal rate of 200 Hz. Selected physical capacity measures were also recorded and correlated with ball release speed. In general, anthropometric and strength measures significantly increased through the 14-year-old to open-age classifications, while a range of correlation coefficients from .50 to .84 was recorded between these physical capacities and ball speed at release. While many aspects of the kinematic data at release were similar, the key factors of release angle and release speed varied for the different age groups.

Transient Analysis of Nonuniform Heat Input Propagation Through a Heat Sink Base

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Srivathsan Sudhakar ◽  
Justin A. Weibel
Keyword(s):  
Heat Source ◽  
Heat Input ◽  
Heat Sink ◽  
Three Dimensional ◽  
Temperature Response ◽  
Flow Distribution ◽  
Temporal Variations ◽  
Step Response ◽  
Dimensional System ◽  
Two Phase

For thermal management architectures wherein the heat sink is embedded close to a dynamic heat source, nonuniformities may propagate through the heat sink base to the coolant. Available transient models predict the effective heat spreading resistance to calculate chip temperature rise, or simplify to a representative axisymmetric geometry. The coolant-side temperature response is seldom considered, despite the potential influence on flow distribution and stability in two-phase microchannel heat sinks. This study solves three-dimensional transient heat conduction in a Cartesian chip-on-substrate geometry to predict spatial and temporal variations of temperature on the coolant side. The solution for the unit step response of the three-dimensional system is extended to any arbitrary temporal heat input using Duhamel's method. For time-periodic heat inputs, the steady-periodic solution is calculated using the method of complex temperature. As an example case, the solution of the coolant-side temperature response in the presence of different transient heat inputs from multiple heat sources is demonstrated. To represent a case where the thermal spreading from a heat source is localized, the problem is simplified to a single heat source at the center of the domain. Metrics are developed to quantify the degree of spatial and temporal nonuniformity in the coolant-side temperature profiles. These nonuniformities are mapped as a function of nondimensional geometric parameters and boundary conditions. Several case studies are presented to demonstrate the utility of such maps.

The Research on Steering Fracture Numerical Simulation

2013 ◽  
Vol 734-737 ◽  
pp. 1488-1492
Author(s):  
Zhen Yu Liu ◽  
Li Hong Yao ◽  
Hu Zhen Wang ◽  
Cui Cui Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Simulation Method ◽  
Production Performance ◽  
Phase Flow ◽  
Water Production ◽  
Two Phase ◽  
Fractured Well

The fractures after artificial steering fracturing appear in shades of curved surface. Aiming at the problem of steering fracture, in the paper, numerical simulation method under the condition of three-dimensional two-phase flow is presented based on finite element method. In this method, of steering fracture was achieved by adopting surface elements fractures and tetrahedron elements to describe formation. By numerical simulation, the change rule of oil and water production performance of steering fractures can be calculated, and then the steering fracture parameters can be optimized before fracturing. A new method was supplied for the numerical simulation of artificial fractured well.

Numerical Simulation of Forced Convective Boiling in a Microchannel

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Yun Whan Na ◽  
J. N. Chung
Keyword(s):  
Numerical Simulation ◽  
Two Phase Flow ◽  
Liquid Velocity ◽  
Flow Boiling ◽  
Simulation Method ◽  
Flow Patterns ◽  
Heat Fluxes ◽  
Phase Flow ◽  
Two Phase ◽  
Convective Boiling

Forced convective flow boiling in a single microchannel with different channel heights was studied through a numerical simulation method to investigate bubble dynamics, two-phase flow patterns, and boiling heat transfer. The momentum and energy equations were solved using a finite volume (FV) numerical method, while the liquid–vapor interface of a bubble is captured using the volume of fluid (VOF) technique. The effects of different constant wall heat fluxes and different channel heights on the boiling mechanisms were investigated. The effects of liquid velocity on the bubble departure diameter were also analyzed. The predicted bubble shapes and distribution profiles together with two-phase flow patterns are also provided.

Impact of Screens Around Bearings on the Flow and Heat Transfer in the Vent and Scavenge Oil Pipes in Bearing Chambers

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Michael Flouros ◽  
Francois Cottier
Keyword(s):  
Heat Transfer ◽  
Hot Spots ◽  
Thermal Effects ◽  
Oil Quality ◽  
Flow Distribution ◽  
Cfd Analysis ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Ansys Cfx ◽  
Oil Flow

The aim of this paper is to investigate, first, the effects of screens introduced around bearings and, second, the use of protruded instead of flush installed vent pipes. The investigation focuses on the air and oil flow distributions and on the heat transfer in the scavenge and the vent pipes in an aeroengine bearing chamber. The flow distribution has an impact on the pipe’s wall temperature distribution with the likelihood of generating hot spots. High temperatures may cause substantial effects on the health of the lubrication system. Problems may range from oil quality degradation to oil self ignition. A steady state CFD analysis of the heat transfer involving the two-phase air and oil flow in these pipes is performed using the ANSYS CFX package. It was demonstrated that whereas screens around bearings reduce the parasitic losses and vent protrusion reduces the oil flow to the air/oil separator, however, due to the oil flow distribution the thermal effects may lead to high material temperatures and to malfunctions in the engine’s lube system.

Analysis of Parallel Microchannels for Flow Control and Hot Spot Cooling

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Stephen A. Solovitz
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Hot Spots ◽  
Hot Spot ◽  
Electronics Cooling ◽  
Flow Distribution ◽  
Reynolds Numbers ◽  
Heat Fluxes ◽  
Cooling Devices ◽  
Parallel Microchannels

Microchannel heat transfer is commonly applied in the thermal management of high-power electronics. Most designs involve a series of parallel microchannels, which are typically analyzed by assuming a uniform flow distribution. However, many devices have a nonuniform thermal distribution, with hot spots producing much higher heat fluxes and temperatures than the baseline. Although solutions have been developed to improve local heat transfer, these are advanced methods using embedded cooling devices. As an alternative, a passive solution is developed here using analytical methods to optimize the channel geometry for a desired, nonuniform flow distribution. This results in a simple power law for the passage diameter, which may be useful for many microfluidic systems, including electronics cooling devices. Computational simulations are then applied to demonstrate the effectiveness of the power law for laminar conditions. At low Reynolds numbers, the flow distribution can be controlled to good accuracy, matching the desired distribution to within less than 1%. Further simulations consider the control of hot spots in laminar developing flow. Under these circumstances, temperatures can be made uniform to within 2 °C over a range of Reynolds numbers (60 to 300), demonstrating the capability of this power law solution.

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