Chamber Technology Goals Used in APEX to Calibrate New Ideas and Measure Progress

Transcription

1 Chambe Technology Goals Used in APEX to Calibate New Ideas and Measue Pogess 1. High Powe Density Capability Aveage/Peak Neuton Wall Load ~ 7 / 10 MW/m 2 Aveage/Peak Heat Flux ~ 1.4 / 2 MW/m 2 (80% of the Alpha Powe Radiated to Fist Wall to ease diveto loading) 2. High Powe Convesion Efficiency (>40%) 3. High Availability (MTBF>43 MTTR) 4. Simple Technological and Mateial Constaints * APEX will exploe concepts with lowe powe density capabilities if they povide significant impovement in powe convesion efficiency o othe majo featues. Technological limits fo conventional concepts have been documented in seveal papes; see fo example APEX pape in Fusion Engineeing & Design, vol. 54, pp (1999)

2 APEX Idea Fomulation Phase Identified Two Classes of Pomising Concepts: 1. Liquid Walls 2. EVOLVE Idea Fomulation Phase : Many ideas poposed and sceened based on analysis with existing tools Liquid Walls and EVOLVE (W alloy, vapoization of Li) wee selected to poceed to the Concept Exploation Phase The Concept Exploation Phase involves extending modeling tools, small expeiments, and analysis of key physics and engineeing issues APEX emains open to new ideas Results of the Idea Fomulation phase ae fully documented on the website and in many jounal publications An Inteim Repot (> 600 pages) fully documents all details: On the Exploation of Innovative Concepts fo Fusion Chambe Technology, APEX Inteim Repot, UCLA-ENG (Novembe 1999).

3 Liquid Walls Emeged as one of the Two Most Pomising Classes of Concepts to poceed to Concept Exploation q Fluid In + Plasma B V J J j B The Liquid Wall idea is Concept Rich a) Woking fluid: Liquid Metal, low conductivity fluid b) Liquid Thickness - thin to emove suface heat flux - thick to also attenuate the neutons c) Type of estaining foce/flow contol - passive flow contol (centifugal foce) - active flow contol (applied cuent) We identified many common and many widely diffeent meits and issues fo these concepts Swil Flow in FRC Plasma-Liquid Inteactions g Fluid Out

4 Motivation fo Liquid Wall Reseach What may be ealized if we can develop good liquid walls: Impovements in Plasma Stability and Confinement Enable high ß, stable physics egimes if liquid metals ae used High Powe Density Capability Inceased Potential fo Disuption Suvivability Reduced Volume of Radioactive Waste Reduced Radiation Damage in Stuctual Mateials -Makes difficult stuctual mateials poblems moe tactable Potential fo Highe Availability -Inceased lifetime and educed failue ates -Faste maintenance No single LW concept may simultaneously ealize all these benefits, but ealizing even a subset will be emakable pogess fo fusion

5 Innovative concepts poposed by APEX can extend the capabilities and attactiveness of solid walls Stuctual mateial is key to extending capabilities of solid walls - High-Tempeatue Refactoy Alloys evaluated: W-alloy selected Helium cooling and Li boiling evaluated EVOLVE - Novel Concept based on use of high tempeatue efactoy alloy (e.g. tungsten) with innovative heat tansfe/tanspot scheme fo vapoization of lithium - Low pessue, small tempeatue vaiations geatly educe pimay and themal stesses - Low velocity, MHD insulato may not be equied - High Powe Density, High Tempeatue (high efficiency) Capabilities SiC/SiC-LiPb limits ae being evaluated SiC may allow high tempeatue, but powe density may be limited

6 APEX Concept Exploation of Liquid Walls and EVOLVE is emphasizing Science and Innovation - Deepe undestanding of phenomena and issues - Advancing the undelying engineeing science - Extending the best available tools though pioneeing model development and caefully planned small laboatoy expeiments - Poposing, advancing, and veifying an impessive list of Innovative Solutions to key physics and engineeing issues Concept Exploation Phase is the cuent phase (it stated in Novembe 1999). A fully detailed technical plan is posted on the web.

7 The Famewok fo APEX Concept Exploation was guided by community delibeations that identified Chambe 5-Yea Objectives Liquid Walls: 1. Fundamental undestanding of fee suface fluid flow phenomena and plasmaliquid inteactions veified by theoy and expeiments. 2. Opeate flowing liquid walls in a majo expeimental physics device (e.g. NSTX) 3. Begin constuction of an integated Themofluid Reseach Facility to simulate flowing liquid walls fo both IFE and MFE. 4. Undestand advantages & implications of using LW s in fusion enegy systems. Solid Walls: 5. Advance novel concepts that can extend the capabilities and attactiveness of solid walls. 6. Contibute to intenational effot on key feasibility issues fo evolutionay concepts in selected aeas of unique expetise

8 APEX is oganized as a patneship between plasma physics and all elements of science & technology OFES VLT / Advisoy Committees Management Abdou Task Coodinato Sawan APEX Steeing Committee Plasma Physics Themofluid Science Technology Elements Task A: Rognlien Liquid suface inteactions Task B: Kaita Liquid bulk inteactions Task V: Kaita Kotcheneuthe Impove plasma pefomance Task II: Moley Fee suface, tubulent MHD fluid contol and intefacial tanspot Task C: Zinkle Mateials Task D: Petti/McCathy Safety & Envionment Youssef / Sawan Neutonics Plasma Liquid Suface Exp. (D-III, CDX-U, PICES) PFC / ALPS Exploe options fo testing in plasma devices Task I: Ying / Ulickson Engineeing issues fo liquid wall designs Task III: Sze / Nelson / Nygen Innovative advanced solid walls Task IV: Wong ALIST Extend capabilities of plasma devices Attactive vision fo fusion

9 APEX is oganized as a patneship between plasma physics and all elements of science & technology OFES VLT / Advisoy Committees Management APEX APEX Steeing Committee Plasma Physics Themofluid Science Technology Elements Plasma - Liquid suface inteactions Plasma - Liquid bulk inteactions Impove plasma pefomance w/ LM Models Expeiments MHD Fluid Contol CFD Pedictive Capbl. Analysis Mateials Safety & Envionment Neutonics Fueling & Heating Plasma Liquid Suface Exp. (D-III,CDX-U, PICES) PFC / ALPS Exploe options fo testing in plasma devices Engineeing issues fo liquid wall designs Innovative concepts fo advanced solid walls ALIST Extend capabilities of plasma devices Attactive vision fo fusion

10 Scientific Issues fo Liquid Walls 1. Themofluid Issues - Intefacial Tanspot and Tubulence Modifications at Fee-Suface - Hydodynamic Contol of Fee-Suface Flow in Complex Geometies, including Penetations, Submeged Walls, Inveted Sufaces, etc - MHD Effects on Fee-Suface Flow fo Low- and High-Conductivity Fluids 2. Bulk Plasma-Liquid Inteactions Effects of Liquid Wall on Coe Plasma including: - Dischage Evolution (statup, fueling, tanspot, beneficial effects of low ecycling - Plasma stability including beneficial effects of conducting shell and flow 3. Plasma-Liquid Suface Inteactions - Limits on opeating tempeatue fo liquid suface

11 Liquid Walls Spaked Geat Inteest in the Community LW Reseach in the US is well Coodinated 1. Themofluid Issues - Modeling (APEX: UCLA, PPPL, SBIR) - Expeiments (APEX: UCLA, PPPL, ORNL, SNL, Univ. of IL) 2. Bulk Plasma-Liquid Inteactions - Modeling (APEX: PPPL, U. Texas, ORNL) - Expeiments (Science Division/OFES: Univ. of Wisconsin) 3. Plasma-Liquid Suface Inteactions - Modeling (Joint APEX/ALPS: ANL, LLNL, othes) - Expeiments (ALPS: CDX-U, DIII-D, PISCES, SNL, Univ of IL) 4. Li Test Module on NSTX (and C-MOD): (APEX, PFC, Physics) * Impotant Note: All the Plasma-Liquid Suface Inteaction Expeiments ae funded unde ALPS, which is unde the PFC Pogam. ALPS Budget is much lage than APEX s. ALPS is not pat of this Chambe Review.

12 LW Themofluid Modeling aimed at undestanding and pedicting flow behavio and intefacial tanspot APEX LW Modeling effot stives to: balance design-focused engineeing analyses with tool development fo geate scientific undestanding and impoved pedictive capabilities utilize and extend state-of-the-at modeling tools - both those developed in fusion and by othe applications fill the void in pedictive capabilities whee none have peviously existed establish connections to and collaboation with scientists in othe fields nationally and intenationally shae knowledge with SBIR paticipants fo the commecial development of modeling tools useful fo fusion

13 Fusion LW Reseaches ae Contibuting to the Resolution of GRAND CHALLENGEs in Fluid Dynamics B = t j = SCALAR TRANSPORT T?C p [ + (V )T] = k T t C + (V )C = D C t 1 µ 1 sµ 0 0 MHD? B+ (V B); B B = 0 Liquid Walls: many inteacting phenomena Tubulence edistibutions at fee suface Tubulence-MHD inteactions Mean flow and suface stability MHD effects Influence of tubulence and suface waves on intefacial tanspot and suface enewal Teaflop Compute Simulation FREE SURFACE PHENOMENA ϕ + (V ) ϕ = 0 t TURBULENCE V 1 + (V )V = - t? 1 + t + g + j B? V = 0 p

14 We ae Extending Computationally Challenging Tubulence Models to Fee Suface, MHD Flows Aveaged Models: Some o all fluctuation scales ae modeled in an aveage sense Supe-computes Lage Eddy Simulation Teaflop computing Tubulence Stuctue Simulated Diect Numeical Simulation length atio: η/l Re τ -3/4 gid numbe: N (3Re τ ) 9/4 Fo Re τ =10 4, N Reynolds Aveaged Navie Stokes Appoach Level of desciption Computational challenge DNS Gives all infomation High. Simple geomety, Low Re LES RANS Resolves lage scales. Small scales ae aveaged Mean-flow level Modeate to high Low to modeate. Complex geomety possible

15 Ou Science-based CFD Modeling and Expeiments ae Utilized to Develop Engineeing Tools fo LW Applications D N S fo fee suface MHD flows developed as a pat of collaboation between UCLA and Japanese Pofs Kunugi and Satake DNS and Expeimental data ae used at UCLA fo chaacteizing fee suface MHD tubulence phenomena and developing closues in RANS models EXPERIMENTS undeway at UCLA fo nea suface tubulence and intefacial tanspot measuements Tubulent Pandtl numbe D Joule Dissipation y + - Re= P_t fo a smooth suface (fom expeimental data) 2 - P_t fo a wavy suface (expected) y / h D I D II K K Extend RANS Tubulence Models fo MHD, Fee Suface Flows K-epsilon RST model 2 Tubulent Pandtl Numbe Cuve1: Available Expeimental Data - Missing and esticted to smooth suface, non-mhd flows Cuve2: Expected fo wavy suface