DropletCombustLect26ME525SP2011

DropletCombustLect26ME525SP2011 - ME 525: Combustion...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
School of Mechanical Engineering, Purdue University ME 525: Combustion Lecture 26: Droplet Evaporation and Burning II Prof. Robert P. Lucht Room 87, Mechanical Engineering Building School of Mechanical Engineering Purdue University West Lafayette, Indiana Email: [email protected] Phone: 765-494-5623 Thursday, April 14, 2011
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
School of Mechanical Engineering, Purdue University Lecture Topics • Model for droplet evaporation and burning. • Evaluation of model constants. • Correction factors.
Background image of page 2
School of Mechanical Engineering, Purdue University Combusting Droplet: Combined Evaporation and Burning
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
School of Mechanical Engineering, Purdue University Combusting Droplet: Combined Evaporation and Burning
Background image of page 4
School of Mechanical Engineering, Purdue University Combusting Droplet: Combined Evaporation and Burning Assume: 1. Droplet is surrounded by a spherical flame in a quiescent, infinite medium 2. Quasi-steady process (droplet radius changes slowly in time) 3. Fuel is single-component, no dissolved gases in droplet (including product gases), no other condensed phases 4. Droplet temperature is uniform: T d is slightly less than T boil 5. Pressure is uniform and constant.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
School of Mechanical Engineering, Purdue University Combusting Droplet: Combined Evaporation and Burning Assume also: 6 . Le = 1 Z = Z F = Z T 7. k g , c Pg , and g are constants evaluated at some mean temperature 8. One step reaction, three species: fuel, product, oxidizer 9. Radiation heat transfer is neglected 10. Buoyancy is neglected 11. At the droplet surface, P F,s = P vap (T s )
Background image of page 6
School of Mechanical Engineering, Purdue University Combusting Droplet: Combined Evaporation and Burning In this problem analysis: Knowns: Unknowns: , ,, 1 so x rT Y   , , , FF sff s sb o i l mY Tr T we assume T T r f r s T s T f Y ox, T Y F,s
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
School of Mechanical Engineering, Purdue University Combusting Droplet: Gas Phase Conservation Equations r>r s Mass Conservation: r s   2 2 v4 F r mr m r const     Assume no dissolved products in the droplet. Outer Region r f r Inner Region Products form a stagnant film in the inner region r s < r < r f
Background image of page 8
School of Mechanical Engineering, Purdue University Combusting Droplet: Species Conservation, Inner Region r s < r < r f Species Conservation   AA A B A B A B A mY m YY m m Y     DD Let species A be the fuel and species B be the product: Pr 0 A FF F B mmY m Y mm  D
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
School of Mechanical Engineering, Purdue University Combusting Droplet: Species Conservation, Inner Region r s < r < r f r r s r f Inner Region Outer Region In spherical coordinates, this becomes: 2 41 F F FF F F F F dY dY mY m Y m dr dr md Y m rY d r      DD D Apply boundary conditions:      , 0 Fs F s s Ff Yr Y T
Background image of page 10
School of Mechanical Engineering, Purdue University Combusting Droplet: Species
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/27/2011 for the course ME 525 taught by Professor Lucth during the Fall '11 term at Purdue.

Page1 / 30

DropletCombustLect26ME525SP2011 - ME 525: Combustion...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online