An empirical examination of the use of non-dimensional wave parameters. Issue 4 (1st October 2020)

• Record Type: Journal Article
• Authors: Lamont-Smith, T.
• Is Part Of: Waves in random and complex media. Volume 30:Issue 4(2020)
• Page Start: 614
• Page End: 631
• Publication Date: 2020-10-01
• Subjects: Wind waves -- wave growth -- fetch laws; Electromagnetic waves -- Periodicals; Electromagnetic waves -- Scattering -- Periodicals; 531.1133
• DOI: 10.1080/17455030.2018.1549761
• Languages: English
• ISSNs: 1745-5030

Abstract

ABSTRACT: A number of datasets from wave tank and field measurements have been assembled from published data. For fixed wind speed, the peak frequency has F ∝ x − 1 / 3 and the significant wave height has H ∝ x 1 / 2 . It has been confirmed following earlier work that wind speed should not be used to non-dimensionalise wave parameters, such as the frequency or the significant wave height because the wind-speed dependence is stronger than expected for the assembled data sets. New parameters have recently been proposed that use fetch, x, and the number of waves to create non-dimensional wave height and wave period, H ~ and T ~ . The applicability of these quantities to the assembled datasets has also been investigated. A new non-dimensional relationship has been found empirically that relates the wave steepness, ak to the dimensionless fetch, ν, of the waves, ( a k ) 2 ν = 130 (or H 2 k 3 x = 260 ), which has the property of being wind-speed invariant. The estimated wind-speed dependence varied with fetch, although the ratio between the wind-speed exponents for H and F remained constant at − 1 / 3 for all fetches.