Numerical evolution of unsteady wake characteristics of H-type Darrieus Hydrokinetic Turbine for a hydro farm arrangement

Design evaluation reviews on the savonius, darrieus, and combined savonius-darrieus turbines

“…The different sizes of Δθ were tested and the results as depicted in Figure 6(a) and (b) were extremely close. Using Δθ of 0.25 and 0.5 82,89 as depicted in Figure 6(a), c p values of both were not much different. Δθ of 0.5 was recommend to used in the simulations by many researchers.…”

“…70 The authors recommended that the k-ω SST confirmed and employed by many researchers was more suitable than the rests 70,108,109 Time step size Time step size (Δt) is a important factor influenced on the precision and the computational time of the unsteady simulations. 89 In fact, the simulation results are unrealistic when using a too large Δt. On the other hand, a too-small Δt requires too much computational time.…”

“…Δθ of 0.5 was recommend to used in the simulations by many researchers. 82,89,111 Consequently, using the larger time step size (Δt) would not affect the simulated results much.…”

“…Time step size (Δ t ) is a important factor influenced on the precision and the computational time of the unsteady simulations. 89 In fact, the simulation results are unrealistic when using a too large Δ t . On the other hand, a too-small Δ t requires too much computational time.…”

“…Δ θ of 0.5 was recommend to used in the simulations by many researchers. 82,89,111 Consequently, using the larger time step size (Δ t ) would not affect the simulated results much.

Figure 6.Time step independence studies by using (a) azimuthal increments of 0.25 o , 0.5 o , 1.0 o , 2.0 o , and 4.0 o 82 and (b) two different time step sizes. 83

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