The UMIST-N Near-Wall Treatment Applied to Periodic Channel Flow

CHAPTER 5. RESULTS 68
a nominal Reτ of 180.
5.1 Steady Flow Results
Although the principal goal of this work is to test the performance of the
UMIST-N method in periodic flow, the steady flow case offers a simpler test
case in which to verify the code.
Steady channel flow results for the k-ε and k-ω models are widely available.
The UMIST-N approach with the standard k-ε model was applied to channel
flow using the TEAM code by Gant during the early development of UMIST-
N [21]. The application of the UMIST-N approach with a k-ω model to
steady channel flow is new.
All the model configurations shown in Table 5.1 were applied to steady chan-
nel flow and the results are presented here. Figures 5.1 & 5.2 show U + and
k + (respectively) plotted against y/δ. Figures 5.3 & 5.4 show a better view
of near-wall values plotted against y + on logarithmic scales. The results are
compared the analytical profiles from Chapter 3 and to the data of Kim et
al. [30], who employed the same Reτ.
The pressure gradient driving the flow was chosen to produce a nominal Reτ
of 180. By applying the definition of Reτ (Equation 3.25), a value of Uτ was
obtained that was used in nondimensionalisation. From Equations 3.23 &
3.19, a corresponding
∂〈P 〉
∂x
was specified. This ∂〈P 〉
∂x
was allowed to drive the
flow, with the actual calculated flow rate being a function of the turbulence
model used.