[ltl]

Hello everyone,

I have some questions about spray modeling setup when adding the water injector in a disel engine? The engine have both disel injectors and water injectors, except the setup of Injectors, how the setup of General, Collision/Breakup/Drag, and Wall Interaction should be changed?

Thank you.

[crajath]

Hi Lynn,

For the water injection, you can refer to the Tumble_GDI_SAGE_transient_RANS example case spray settings for breakup, drag, collision, and wall film. The only thing that needs to be changed is the diffusivity constants which need to be adjusted to our recommendation for water. of course, the liquid properties (liquid.dat) need to reflect the properties of the water used in the experimental setup. Please let us know if you have any questions.

[ltl]

Originally Posted by crajath

Hi Lynn,

For the water injection, you can refer to the Tumble_GDI_SAGE_transient_RANS example case spray settings for breakup, drag, collision, and wall film. The only thing that needs to be changed is the diffusivity constants which need to be adjusted to our recommendation for water. of course, the liquid properties (liquid.dat) need to reflect the properties of the water used in the experimental setup. Please let us know if you have any questions.

Hi Rajath,

I have received your suggestion, thank you very much for your reply.

According to your opinion, if I want to add an additional water injector to the diesel engine.
1. Spray settings for breakup, drag, collision, and wall film can be consistent with the original diesel injection. Am I right?
2. The only thing that needs to be changed is the diffusivity constants which need to be adjusted to our recommendation for water. Since diesel and water are injected at the same time, how should this Mass diffusivity constants be set?
3. The liquid properties (liquid.dat) need to reflect the properties of the water used in the experimental setup, about this I have added water in the parcel simulation.

When I added an additional water injector to the diesel engine to study the impact of DWI:
Firstly, I added water in parcel simulation and made corresponding changes in species;
Secondly, an additional water injector has been added on the basis of unchanged General settings. Since diesel and water are injected at the same time, my question is how to change the Evaporation source, Penalation and Mass diffusivity constants;
Thirdly, the parcel species in the water injector is changed to water, mass fraction=1.0, and the other model settings are consistent with the diesel injector model settings. Do the relevant settings here need to be changed?
Is this setting process correct? Are there any considerations for omissions?

Looking forward to receiving your reply, thank you!

[asofianopoulos]

Hello Lynn,
It is unclear from your message if you are using two separate injector (1 water injector and 1 Diesel injector) or one injector with a water-Diesel blend being injected. Can you clarify that please?
Can you contact us at support@convergecfd.com and share your case setup such that we can help you set it up based on our optimal settings.

Thank you,
Best regards,

Aimilios Sofianopoulos, Ph.D.
Senior Research Engineer - Applications
Convergent Science Inc.