Influence on Stern Flaps in Resistance Performance of a Caterpillar Track Amphibious Vehicle

Abstract

In order to reduce the resistance and increasing speed for a caterpillar track amphibious vehicle (CTAV), the stern flaps were applied and the influence was researched. Numerical simulations performed by STAR-CCM+ and model towing test reveal that stern flaps have greatly reduced the resistance, trim, and sinkage of the CTAV when the length Froude number is between 0.63 and 1.05. The length and flap angle were optimized by numerical simulation. In addition, the residual resistance plays a dominant role in resistance reduction, which contributes to more than 90% of the total resistance reduction. Installing stern flaps increase the vehicle waterline by 7% and enhance the virtual-length effect. Furthermore, the running attitude becomes steadier, thereby decreasing the trim and sinkage. Therefore the resistance performance of the CTAV can be enhanced by installing stern flaps with a proper length at an optimal flap angle. INDEX TERMS Caterpillar track amphibious vehicle, CFD, resistance performance, running attitude, STAR-CCM+.

Influence of Flanks on Resistance Performance of High-Speed Amphibious Vehicle

“…The model calculation domain is shown in Figure 6. According to the guidance of ITTC [34], the orthogonal calculation domain of 5L pp × 3L pp × 2L pp was established, where L pp is the length between the head and tail of the vehicle model [12]. the vehicle's attitude.…”

“…Moreover, the air injection devices will increase weight and draft, negatively affecting the vehicle's resistance to wind and waves. Sun et al studied the effect of stern flaps on a caterpillar track amphibious vehicle (CTAV), which will perform better by improving trim, lessening draft, and increasing virtual length [12]. When Fr is between 0.63 and 1.05, the drag reduction impact can reach 34.31%.…”

Pengaruh Penambahan Variasi Geometri Stern Flap Terhadap Nilai Hambatan Pada Kapal Patroli Perikanan

“…Upaya sederhana yang dinilai mampu memperbaiki performa hidrodinamika kapal patroli yaitu dengan instalasi appendages seperti stern flap (Song et al, 2019). Kombinasi antara stern flap dengan transom buritan dapat memperbaiki bidang aliran wake dengan berkurangnya ketinggian dan lembah gelombang (Klara et al, 2020), gaya drag dan hambatan gelombang dapat berkurang, hingga meminimalisir hilangnya daya (Sun et al, 2020). Geometri stern flap yaitu berupa perpanjangan pelat pada transom kapal yang diatur dengan sudut tertentu terhadap garis air (Yaakob, Shamsuddin and Koh, 2012).…”

“…Pada penelitian ini ditetapkan penggunaan metode komputasi numerik Computational Fluid Dynamics (CFD) berdasarkan persamaan Reynolds-Averaged Navier Stokes (RANS) dengan teknik solusi numerik Finite Volume Method (FVM) untuk mengetahui nilai hambatan total serta nilai 2-DOF (Degree of Freedom) kapal yaitu heave (gerak translasional pada sumbu Z) dan pitch/ trim (gerak rotasional pada sumbu Y) di perairan tenang dengan permodelan turbulensi k-ε, model fisika fluida eulerian multiphase yang terdiri dari fasa air serta udara dan dengan pendekatan Volume of Fluid (VOF) untuk merepresentasikan kondisi free surface (Sun et al, 2020). Meshing yang digunakan dalam penelitian ini menggunakan metode overset grid dimana objek geometri didiskritasi menggunakan prinsip donor-acceptor cells yang terdiri dari geometri overset sebagai akseptor dan background sebagai pendonor (Fathuddiin et al, 2020).…”

“…Overset mesh merupakan metode meshing dimana dilakukan dengan cara donor-acceptor cells (Fathuddiin et al, 2020). Ukuran kerapatan mesh dari background dan overset harus memiliki dimensi yang sama agar data dapat ditransfer secara linear (Sun et al, 2020). konsentrasi mesh berdasarkan koordinat x, y, dan z dengan metode anisotropic mesh.…”