Experimental Comparison of Plunger-Type Wavemaker Models with Mean Flow

Plunger-type wavemakers are advantageous for lab-oratory water channels due to their ease of use and ability to allow mean flow across the lateral boundary. While many methods exist for predicting wave amplitude, experimental work often remains limited and typically excludes mean flow. This study extends a recently developed analytical model based on the conservation of mass to include mean flow, and compares it to a semi-analytical Plunger-Type with Flow (PTF) model based on potential flow theory. Both models are experimentally validated across a range of wave parameters, including mean flow, frequency, and stroke amplitude. Results indicate that the new Equal Volume with Flow (EVF) model predicts the experimental ratio of wave amplitude to stroke amplitude more accurately, with an average error of 34.97%, compared to 83.71% for the PTF model. After applying an operational correction, the average error decreased to 21.71% for the EVF model and 19.43% for the PTF model. Thus, while both models are comparable with a correction factor, the EVF model is easier to implement.