Comparative Analysis of CTF and Trace Thermal-Hydraulic Codes Using OECD/NRC PSBT Benchmark Void Distribution Database

Table 2

CTF models for turbulent mixing and void drift.

	Mass exchange of the phase 𝑘: 𝑚̇^TM𝑘=−𝛽TP𝐺𝜌𝛼𝑘,𝑗𝜌𝑘,𝑗−𝛼𝑘,𝑖𝜌𝑘,𝑖
Turbulent mixing	Momentum exchange of the phase 𝑘: 𝐼̇^TM𝑘=−𝛽TP𝐺𝜌Δ𝐺𝑘𝐴
	Energy exchange of the phase 𝑘: 𝑄̇^TM𝑘=−𝛽TP𝐺𝜌Δ(𝛼𝑘𝜌𝑘ℎ𝑘)𝐴
	User specified single value based on experimental data or
Single-phase turbulent mixing coefficient	internally calculated using the correlation by Rogers and Rozehart:
	𝛽SP=12𝐷0.0058^gap𝐷rod^−1.46Re^−0.1𝐷1+^hyd,𝑗𝐷hyd,𝑖^1.5𝐷hyd,𝑖𝐷rod
	Two-phase multiplier by Beus: 𝛽TP=ΘTP𝛽SP;
Two-phase turbulent mixing coefficient	ΘTP=1+(Θmax𝑥−1)𝑥max  if 𝑥≤𝑥max,
	ΘTP=1+(Θmax𝑥−1)^max−𝑥0𝑥−𝑥0  with  𝑥0𝑥max=0.57Re^0.0417 if 𝑥>𝑥max
	with Θmax=5 and 𝑥max=0.4𝑔𝜌liq(𝜌liq−𝜌vap)𝑑hyd𝐺tot+0.6/𝜌liq𝜌vap+0.6
	Mass exchange of the phase 𝑘: 𝑚̇^VD𝑘=𝛽𝐺𝜌𝛼𝑘,𝑗,EQ𝜌𝑘,𝑗,EQ−𝛼𝑘,𝑖,EQ𝜌𝑘,𝑖,EQ𝐴
	Momentum exchange of the phase 𝑘: 𝐼̇^VD𝑘=𝛽𝐺𝜌𝐺𝑘,𝑗,EQ−𝐺𝑘,𝑖,EQ𝐴
Void drift	Energy exchange of the phase 𝑘:
	𝑄̇^VD𝑘=𝛽𝐺𝜌𝛼𝑘,𝑗,EQ𝜌𝑘,𝑗,EQℎ𝑘,𝑗,EQ−𝛼𝑘,𝑖,EQ𝜌𝑘,𝑖,EQℎ𝑘,𝑖,EQ𝐴,
	𝛼𝑘,𝑗,EQ𝜌𝑘,𝑗,EQ−𝛼𝑘,𝑖,EQ𝜌𝑘,𝑖,EQ=±𝛼vap𝜌𝑘𝐺tot𝐺tot,𝑗,EQ−𝐺tot,𝑖,EQ