Download presentation
Presentation is loading. Please wait.
Published byBeverley White Modified over 9 years ago
2
Post Injection Process in Port Injection Systems P M V Subbarao Professor Mechanical Engineering Department Models Based Predictions of Multi-physics of Spray …...
3
Frequency diagram of droplets mean diameter Distribution Rosin & Rammler Distribution
4
Representative Mean Diameter Introducing the definition of SMD: where d nozz is the nozzle diameter, μ f, μ g are the fuel and gas dynamic viscosity, respectively, Re the Reynolds number and We the Weber number. German scientist J. Sauter : 1920 Empirical Formula for prediction of possible SMD:
5
Injection Characteristics
6
Fuel Droplet Dynamics : Prediction of Arrival
7
YAMAHA MOTOR TECHNICAL REVIEW Shoichi Kato, Takanori Hayashida, Minoru Iida
8
Proposal - 1
9
Proposal - 2
10
Proposal - 3
11
Proposal - 4
12
Experimental Results to Select Right Arrival Time AFR 14.5, Coolant Temp. 80 ℃ MEP 380 kPa,
13
The System Reliability
14
Flow Simulation Considering the air velocity distribution and distance between the injection nozzle and intake valve, the timing at which the fuel spray reaches the intake valve and enters the cylinder is predicted.
15
Droplet dynamics During the spray penetration, there is a drag force exerted on the droplets from the surrounding gases, which tends to decrease the relative velocity between the drop and the gas flow. From the Newton's Second Law, the equation is: Where d is the droplet diameter, u g and u f are the velocities of the gas flow and the liquid fuel droplet, respectively. And the drag coefficient C D is given as:
17
Droplet Impingement Process
18
Variation of Volume Fluxes
19
Deposited Film Mass Fraction
20
Spray Length
21
Simplified Engineering fuel Evaporation model In a simplified engineering model a representative diameter for the entire group is defined to compute evaporation rate. Equivalent diameter of same number of uniformly sized droplets having same total surface area.
22
Details of Heat and Mass Transfer across Droplet
23
Droplet evaporation The droplet evaporation rate is given by where d is the droplet diameter, D AB the gas diffusivity, Sh* the non-dimensional Sherwood number, and B m the mass transfer number. The mass transfer number B M is equal to:
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.