To adequately analyze the flow in a pipe or duct network system, traditional node-based junction coupling methods require junction losses, which are specified by empirical or analytic correlations. In this paper, a new finite volume junction coupling method using a ghost junction cell is developed by considering the interchange of linear momentum as well as the important wall effect at the junction without requiring any correlation on the junction loss. Also, boundary treatment is modified to preserve the stagnation enthalpy across boundaries, such as the pipe end and the interface between the junction and the branch.The computational accuracy and efficiency of Godunov-type finite volume schemes are investigated by tracing the total mechanical energy of rapid transients due to sudden closure of a valve at the downstream end. Among the approximate Riemann solvers, the proposed RoeM scheme turns out to be more suitable for finite volume junction treatment than the original Roe's approximate Riemann solver because of conservation of the stagnation enthalpy across the geometric discontinuity. From the viewpoint of computational cost, the implicit LU-SGS time integration is appropriate for steady and slow transients, while the explicit third-order TVD Runge-Kutta scheme is advantageous for rapid transients.(iii) A single momentum flow exists at the junction node: lim x i →0 + s i ( p + U 2 ) i = P (iv) A geometry and flow-dependent pressure loss exists: pk = p k −f (k,k) Here, x i and s i denote the axial distance from the junction node, and the cross-section area of pipe i, respectively.f (k,k) is the pressure loss along the streamline (k,k). k andk indicate the ingoing and outgoing pipe indices, respectively.Guinot [8] introduced a Godunov-type finite volume scheme for one-dimensional pipe flow, and proposed an iterative junction coupling method to specify boundary conditions for adjacent pipes from the coupling conditions (i) and (iv). Kiuchi [9], Guy [10], and Osiadacz [11] proposed another iterative method to calculate the junction pressure. Recently, Banda et al. [14] analyzed the coupling conditions (i) and (ii) or (i) and (iv) from a mathematical point of view, and proved the well-posedness. Colombo and Garavello [12] have proposed similar coupling conditions (i) and (iii), and proved the well-posedness.The traditional node-based junction treatments depend on many loss coefficients at the junction, as shown in the coupling condition (iv), to properly reflect the momentum interaction at the junction. However, the junction losses are often incorrectly assigned or unwillingly neglected in complex flow network applications when the connected branch angle is arbitrarily three-dimensional and/or the number of branches is greater than four. In this case, the analytic correlations are very difficult to derive, and empirical correlations are rarely available. In practical engineering design, the junction losses are negligible in most long-pipe systems, but the losses are no longer trivial for short-pipe systems bec...