Towards the Development of a Preliminary Combustor Design and Sizing Computational Software

Part III: Development of Physics Based Emission Model

John Melchizedek John Britto

Thermal Power MSc, Aerospace Propulsion Option

School of EngineeringJanuary 2015

Supervisor: Dr. Vishal Sethi

Objective

Methodology

Develop models to approximate the

flow characteristic of combustors

Integrate flow models and Chemical

Reactor Network (CRN) into unified

emission model

CRN

E3 Combustor

Emission

Model

Target

Physical

Parameters

Model

Parameters

Flow Model

Dimension

Flow Splits

Emission

Generalization

Experimental DataDevelopment

Variable

Model Overview

Input

Jet Penetration

Flow Splits

Dimension

Conclusion

Key Reference

Recirculation

Apeak

Flow

splits

Mixing

Length

Jet Mixing

Radial

Growth

Fuel DistributionNW I

MID I

CORE I

RECIR I

RECIR O

CORE O

MID O

NW O

RTDP

0

5

10

15

20

25

30

35

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Em

iss

ion

In

de

x

fuel flow

EI NOx predicted EI NOx actual EI CO predicted EI CO actual

A new methodology and emission model

was successfully developed

Model can be extend to Radially staged

combustors and converted into 3D by

circumferentially arranging reactors

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0

10

20

30

40

50

60

70

80

90

100

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Len

gth

(cm

)

Ra

diu

s (

%)

Fuel flow (kg/s)

Model Parameters

R peak R growth L mixing

Emission Indices

Burrus, D.L., et al, “Energy Efficient Engine: Component Development and Integration:

Single-Annular Combustor Technology Report”, NASA CR-159695.

Tavg

NASA CEA 𝜙

𝒎𝒂𝒓𝒆𝒈 = 𝒎𝒇𝒓𝒆𝒈

𝝓 × 𝑭𝑨𝑹𝑺

Gu

ess

𝑚𝑎𝑡𝑜𝑡𝑎𝑙 = 𝑚𝑎𝑟𝑒𝑔

Ge

ne

raliz

atio

n

IF

Ye

sIF NO

Fuel

+Air

Fuel

Air