# Influence of Right Triangular Prism Rough Beds on Hydraulic Jumps
## 1 Introduction
Similarly, [PERSON] and [PERSON] [2] also investigated experimentally with a wide variation in wave steepness values \(t/s\) (\(s\) is a sinusoidal corrugation wavelength) of \(0.286\leq t/s\leq 0.625\) and indicated that the jump length was shorter than the smooth bed by about 50%. [PERSON] and [PERSON] [4] performed 42 tests to evaluate the influence of triangular corrugated beds on hydraulic jumps. The results showed that for \(6.1\leq F_{\rm{r1}}\leq 13.1\) and \(0.22\leq t/s\leq 0.29\) the sequent depth and jump length was reduced by about 25% and 54.7%, respectively. [PERSON] and [PERSON] [13] used a numerical simulation method to define hydraulic jumps on trapezoidal corrugated beds for \(4.96\leq F_{\rm{r1}}\leq 13.2\). The study results showed that this rough bed type significantly decreased jump length. [PERSON] and [PERSON] [5] applied the Flow-3D model to investigate the characteristics of free and submerged hydraulic jumps on different rough beds (three roughness shapes, i.e., triangular, square, and semioval) for \(0.2\leq t/l\leq 0.5\) (\(l\) is the distance of roughness). The results showed that the different rough beds reduced the conjugate depth and jump length compared with a smooth bed. However, the diverse geometrical characteristics of the rough bottoms combined with the different layouts on the channel bed cannot be covered with that research. Thus, the formation of a hydraulic jump and the energy dissipation efficiency of the rough bed still need more research to clarify their characteristics. Therefore, this research contributes to a better understanding of hydraulic jumps on rough beds. Based on the study of [PERSON], [PERSON] et al. [4], this paper proposes four new types of rough beds, which have geometry characteristics and arrangements of the rough elements on the channel bed different from the previous studies mentioned [1; 2; 4; 7; 8; 9]. These rough beds were created by rough elements, which have a right triangular prism-type shape and are arranged continuously or discontinuously on the channel bed, with the scope of the research focused on flow conditions. The geometry characteristics of rough elements were extended as follows: the relative high roughness of \(0.67\leq t/y_{1}\leq 1.33\), the wave steepness values (\(t/s\)) of \(0.67\leq t/s\leq 1.33\) (\(s\) is the bottom width of the roughness element), the relative distance of the roughness elements of \(0.0\leq L_{\rm{s}}/y_{1}\leq 4.0\), the angle of the upstream and downstream face of the right triangular prism element of \(0.0\leq m\leq 1.5\), the initial Froude numbers \(4.8\leq F_{\rm{r1}}\leq 9.4\), discharge per unit width \(q\) (m\({}^{2}\) s\({}^{-1}\)), \(0.0276\leq q\leq 0.1533\), and the initial Reynolds number \(27.31\times 10^{3}\leq Re_{\rm{r1}}\leq 151.80\times 10^{3}\). This work also uses the entropy production theory to account for energy dissipation location in a hydraulic jump. On the other hand, this study provides helpful recommendations for determining rough bed geometrical characteristics for designing or renovating stilling basins for low-head irrigation works downstream of highway sewers.