lh2 manifold r & d

LH2 Manifold R & D1. The driving physics issue in Mucool LH2 R & D

is now fluid flow and heat removal2. Two separate absorber designs

1. What is “certification”?2. What are the fundamental limits of operation?

3. Flow simulations1. What are the first direct measurements?2. What level of complication do we need?

4. Flow tests1. Schlieren IN PROGRESS2. Infrared3. “KEK-II” pre-stage

5. Instrumentation and heaters1. How will the simulations inform us?

LH2 flow issues…Our Challenge: Large heat deposition and beam path is through entire

volume absorber!1. Liquid must move everywhere2. Need gauge of temperature and density uniformity

Questions:

• What computations are helpful? • Are realistic flow simulations realizable? • What tests will be useful, and how quantitative can they be? • What level of instrumentation will convince us of sufficient

temperature uniformity?

Force flow simulations3 dimensional FE simulations are possible but CPU intensive (W. Lau, S. Wang)

3-dim and 2-dim flow simulations are consistent – use 2 dim fordesign and iteration. Preliminary results indicate that “bellows” window has better flow pattern in window volume.

Convection flow simulations

Heating Coil

Liquid Hydrogen

3-d grid:

Lau/Wang FE 3-d flow simulation of KEK LH2 absorber:

K. CasselCFD:

First answers from simulations

1. The simulations are showing us some very interesting and complicated behaviors. They can also tell us simple things like temperature and pressure!

2. Simplified simulations will be necessary to verify first experimental results.

3. CFD and 3-dim FEA’s… are these complimentary ..does one method better handle “anomolies” better than the other

4. Where is it easy to iterate?5. What would be “data of merit”?

First answers from experiments

1. Qualitative behavior of heat movement at window boundary

2. Temperature measurements at a very finite number of points

3. Heat transfer coefficients:1. LHe - LH22. Al - LH2

4. Limitations of instrumentation and heating from safety guidelines

Near term R & D 1. What is the effect of heating the windows?2. What are the limiting cryo-loop factors in nozzle

designs (forced-flow)?1. P from maximum LH2 flow2. Nozzle speed and fluid circulation (minimal speed)3. Minimize number of nozzles

3. Can convection in either model prevent any “dead zone from developing?

4. Turning on/turning off : transients

Flow TestsSchlieren testing of convection flow (water) test at

ANL (more quantitative program to run in 2003) J. Norem, L. Bandura