Process Overview

NICHE's convergent design process combines insights from field observations, experiments at a geographically-distributed Physical Design Testbed (PDT) and computational fluid dynamics models (CFD) to determine key design parameters. Learn more about the process below, executed over a multi-year timeline.

Key Design Parameters

Water Design Parameters

Water type (fresh vs. salt)
Wave characteristics & storm surge
Flume dimensions
Variable bathymetric profile
Wave generator type
Sediment pit
Current generation
Wind-water fetch length

Wind Design Parameters

Maximum Wind Speed
Wind Test Section Height
Wind Test Section Blockage
Wind Tunnel Length
Reynolds Number Similarity and Scaling
Circuit Type – Open and Closed Modes

Wind-Wave Experimental Insights

Experiments were conducted using Physical Design Testbed (OSU-LWF, UCSD-SOARS, UM-SUSTAIN) to study:

Wind wave interaction and scaling
Required channel length
Required fetch length
Beach shape
Sea spray effects
Seawater vs fresh water

Role of CFD

Coupled wind-wave CFD model was validated using PDT experimental data and used to establish:

Wind injection location (required fetch)
Maximum water level
Headspace height

CFD is being utilized to geometrically optimize the aerodynamic flowpath and key circuit elements (contraction, collector, corners, diffusers, screens) and establish performance parameters and power requirements.

CFD modeling also guided the design of nonstationary flow simulator, later tested at UF-BLWT.

Role of Field Observations

Field observations from legacy storm events demonstrate that no existing facility can achieve the wave heights or wind velocities of contemporary events. These establish the intensities NICHE must target to replicate real-world severe weather events.

Role of Community Input

Initial Workshops

MsRI Workshop (Aug 2020) and USA Flume Workshop (May 2023) with dozens of attendees identified gaps in testing capabilities across the wind and coastal communities.

Stakeholder Interviews

Dozens of semi-structured interviews with key informants, including the NHERI Tech Transfer Committee, provided valuable insights into user needs, expectations and research translation requirements.

Convergence Workshops

Series of online workshops were coducted for broad community input, progressively engaging specific use cases to explore needs at all points of the project life cycle.

Facility Interviews

Beyond the expertise in large-facility operations on the Design Team, interviews were conducted with other major facility operators to identify key lessons learned, pain points and capacities required for streamlined facility operations.