# Presentation: 272777

## Combustion Simulation and Modeling

**Combustion Simulation ****and Modeling**

**Presented at the CSET Workshop **
**Monday, July 21, 1998**
**Willowbrook, IL**
**Steve Binkley**
**(925)294-2174**
**jsbinkl@sandia.gov**

## Combustion Simulation and Modeling

**Combustion Simulation and Modeling**

**Goals:**
**Develop ****tools and models**** that enable fully predictive simulation of combustion processes**
**Develop underlying ****scientific understanding**** of combustion phenomena**
**Demonstrate ****the use of these tools through application to combustion systems with realistic geometries**
**Boilers and furnaces, Internal Combustion Engines, Turbines**
**Strategies:**
**Use MPP technology to simulate combustion systems**
**Full integration among DOE labs and universities**
**Partnership with US combustion-related industries**
**Outcomes:**
**New scientific understanding and tools**
**Concepts for improved combustion devices**
**Improved efficiency & reduced emissions**
**Introduction and incorporation of MPP approach in US industries**

**Notes:**
Insofar as combustion accounts for 85% of the energy production in the U.S., fundamental understanding of and quantitative, predictive capability in combustion are central to DOE’s energy mission.
Insofar as Industry remains the primary transforming agent of scientific knowledge into technology, the fundamental knowledge and capability gained in this initiative will be used primarily by industry for the design of practical combustion devices.  However, the proposed effort is basic in nature, of benefit to the country as a whole, and is not “corporate welfare.”
The level of simulation science, and the use of massively parallel computers goes completely beyond what industry can accomplish during the next decade.
The scale of the problem demands an integrated, national program involving DOE laboratories and universities to make the proposed leap in detailed understanding and predictive capability.
This initiative will emphasize the complete characterization of combustion processes in a spectrum of combustion devices, not just internal combustion engines.
The problem will be attacked from a “system” perspective
All aspects of the combustor, from fuel formulation, through the combustion process, to any after treatment that may be required to handle unwanted emissions, will be considered.

## Why combustion?

**Burning of fossil fuels is the source of ~85% of the energy used annually in the US**
**Burning of fossil fuels is the major source of anthropogenic atmospheric emissions**
**Regulations on the burning of fossil fuels are a major component of US energy and environmental policy**
**Although combustion is one of the oldest technologies, we still do not possess a fundamental understanding of combustion processes**

## CSMI:  Combustion Simulation and Modeling Initiative

**Predictive calculations of combustion must include:**
**chemistry**
**hydrodynamics**
**materials**
**Benefits include**
**reduced emissions**
**improved efficiency**

## New Emissions Regulations are on the Horizon

**New Emissions Regulations are on the Horizon**

**Emissions requirements are becoming increasingly stringent**
**Diesel and gasoline ICEs**
**Boilers**
**Furnaces **
**Turbines**
**Requirements beyond 2004 will be difficult to meet with existing understanding**

**Notes:**
The public demand for clean air is driving state and federal emission regulations to ever more stringent levels of control.
This is just one example of the regulatory climate--that for heavy duty diesels (such as are used for heavy trucks).
Industry might be able to attain the proposed 2004 standards.
Beyond that, as emissions are regulated down to near zero by about 2010, new understanding and models are the only hope.
Similarly stringent regulations are being developed for all classes and types of combustion devices, even in some instances lawnmower engines.  
In particular, light-duty diesels may one day be used to increase fleet efficiency in cars and light trucks, but...
 Current emissions standards for light-duty diesels are less stringent than for gasoline engines.
 As more of the auto and light-truck fleet switches to diesels, diesel emissions will emerge as a major contributor to environmental decline.
 Consequently, more stringent emissions standards will be required for light-duty diesels to meet ambient air quality standards

## New Scientific Understanding Is Needed ...New Scientific Understanding Will Be Gained

**New Scientific Understanding Is Needed ...****New Scientific Understanding Will Be Gained**

**Chemical Sciences**
**gas-phase reactions****	****	****–****  multiphase reactions**
**fuel formulation****	****	****–****  catalysts**
**fuel mechanisms****	****	****–****  speciation**
**Materials Sciences**
**lubrication****	****	****	****–****  rheology**
**alloys****	****	****	****–****  adhesion**
**friction & wear****	****	****–  ****erosion and corrosion**
**Engineering Sciences**
**sprays****	****	****	****–****  droplets**
**radiation****	****	****	****–****  turbulence models**
**Computer Science**
**grid approaches****	****	****–****  visualization**
**data storage****	****	****–****  data compression**

**Notes:**
New science will be required to solve the combustion problem, and new science will result from this initiative.  Because of the complexity of the combustion process, several disciplines are involved.  In each of chemistry, materials, engineering and computer science, there are many challenging research problems.  
For example, consider boilers.  The most pressing technological problems in entrained-flow and recovery boilers (used for power generation and industrial process heat, respectively) are
developing improved alloys for the steam tubes that can handle steam at higher temperatures and pressures
finding materials that will reduce fouling and slagging (ash deposition) that is a major problem when co-firing coal and biomass.
Another example:  Our knowledge of chemistry at surfaces, whether in combustion chambers or in exhaust treatment catalysis, is at a very rudimentary level because of the complexity of the role of surface structure in determining surface chemistry.  Predictive models do not yet exist and may emerge only from heroic scale calculations.

## The CSMI Scientific Approach: Divide Time and Space into Distinct Regimes

**The CSMI Scientific Approach: ****Divide Time and Space into Distinct Regimes**

_**Time & Length Scales**_

**10****-15**** **** *****t****** ***** 10****-9**** seconds**
**10****-10**** **** *****l***** **** 10****-6**** meters**

**10****-9**** **** *****t****** ***** 10****-3**** seconds**
**10****-6**** **** *****l***** **** 10****-2**** meters**

**10****-3**** **** *****t****** ***** 10****-4**** seconds**
**10****-2**** **** *****l***** **** 10****+2**** meters**

_**Experiments**_

**Enabling CS & App.. Math**

**Atomistic & Materials**
**Simulations**

**Fine-continuum**
**DNS Simulations**

**Device-level**
**Simulations**

**Requirements**

**Requirements**

**Mechanisms &**
**Materials Properties**

**Physical & Chemical**
**Models**

_**Simulations**_

**Enabling CS & App.. Math**

**Enabling CS & App.. Math**

**Notes:**
Even with the types of computers that are projected to exist in the next decade, it will not be possible to simply grid up your typical combustion device on the computer and crunch out the solution.  The ranges of time and length scales are just too great.  The approach we will use is to divide the time and length scales into three distinct regimes, each of which can be treated separately.  
At atomic and molecular scales, relevant phenomena are quantum in nature.  Determining the characteristics of fuel chemicals and materials will be done using ab initio techniques that solve the Schrodinger equation.  With the levels of computer power that are projected to be available, it will be possible to compute all needed information (e.g. reaction rates) for the relevant fuels.
At the “fine continuum” scale, we will resort to direct numerical solution (DNS) of the Navier-Stokes equations, using the chemistry determined in the step above.  This will allow us to resolve computationally all pertinent aspects of turbulent combustion, and will enable development of models for turbulence, sprays, mixing, wall interactions, etc., that can be fed into the models at the engineering level.
Finally, at the scale of combustion devices with characteristic geometries, we will use finite-element or finite-volume techniques that embody the models described above.  By varying the complexity of the models and the sophistication of the grid representation, we believe that predictive simulations can be done.  
Note also the need for experimental validation at all scales.  New detailed models and new theories will challenge experimentalists.

## Computational Requirements:  Fine-Continuum

**Year****	****Tflop****	****Memory****	****3D Turbulent DNS with Reduced Chemistry**
- FY00	  	5	 310 GW	Natural gas:  	17 species, 63 reactions
- FY03		40	 2.5 TW	Gasoline fuel surrogate:	12 species, 18 reactions
- FY08		200	12.5 TW	Diesel fuel surrogate:	12 species, 18 reactions

## Integration Among DOE Laboratories and Universities

**Integration Among DOE Laboratories and Universities**

**Participating DOE Laboratories**
**Argonne****	****	****	****–  Los Alamos**
**Brookhaven****	****	****–  Oak Ridge**
**Lawrence Livermore****	****–  Pacific Northwest**
**Lawrence Berkeley****	****	****–  Sandia**
**We will engage the university research community**
**Examples of universities actively involved in combustion research**
**	****U. Wisconsin****	****	****	****Princeton**
**	****Stanford****	****	****	****	****UC San Diego**
**	****MIT****	****	****	****	****Utah**
**	****UC Berkeley****	****	****	****Florida State**
**	****CalTech****	****	****	****	****...**

**Notes:**
Integration among institutions is absolutely vital to making this initiative succeed.  To date, the DOE multiprogram labs listed above have all been involved.  I cannot overstate the amount of integration that will be required.  Because so many different skills are required, and the people are so dispersed, a new paradigm of research, collaboration, and development will be required.

We are planning to involve universities in the initiative in much the same way the ASCI program has worked.  There are very significant combustion programs at a number of universities, such as those listed here.

## Partnership with US Combustion-Related Industries

**Partnership with US Combustion-Related Industries**

**Partnership with US industries is essential**
**Internal combustion engines**
**Chrysler, Ford, General Motors**
**Caterpillar, Cummins, Detroit Diesel**
**Boilers and furnaces**
**Babcock & Wilcox**
**ABB Combustion Engineering**
**...**
**Turbines**
**General Electric**
**Pratt & Whitney**
**Caterpillar**
**Significant partnerships exist today**
**Diesel Collaboratory**
**CRF programs**
**Laboratory-industry CRADAs (ANL, ORNL, LBNL, LANL)**

**Notes:**
Similarly, partnership with US industry is vital.
They have the expertise in real combustion systems, and know what the real-world problems are.
They also are where the modeling capabilities we are developing will ultimately be tested against real-world problems.
As a consequence, their early involvement is vital.  The ones listed in red have already been contacted.  So far, the responses have been very favorable.  
Significant partnerships exist already.
An example is the Diesel Collaboratory that involves Sandia, LBNL, LLNL and LANL, the three diesel engine manufacturers (Caterpillar, Cummins and Detroit Diesel), ER/BES and EE/OTT, and the University of Wisconsin.
There are numerous partnerships in Sandia’s Combustion Research Facility, and lab-industry CRADAs involving the labs listed.

## What I would like to see us accomplish here ...

**Begin a dialog between CSM and CSET**
**Achieve a mutual understanding of CSM’s CSET needs**
**Start a process for negotiating these needs into requirements**
**Develop an understanding for what types of cset activities should be pursued directly in the CSM**
**Develop ideas that will lead to new methods of interaction between CSM and CSET**