From 78f7d98fbbabf2289e9171985faa0df8b6435e60 Mon Sep 17 00:00:00 2001 From: Michael Zingale Date: Thu, 19 Sep 2024 19:17:35 -0400 Subject: [PATCH] separate out the wave speeds --- pyro/compressible/riemann.py | 208 +++++++++++++++-------------------- 1 file changed, 89 insertions(+), 119 deletions(-) diff --git a/pyro/compressible/riemann.py b/pyro/compressible/riemann.py index 789bfe024..d567c6c32 100644 --- a/pyro/compressible/riemann.py +++ b/pyro/compressible/riemann.py @@ -593,6 +593,91 @@ def riemann_prim(idir, ng, return q_int +@njit(cache=True) +def estimate_wave_speed(rho_l, u_l, p_l, c_l, + rho_r, u_r, p_r, c_r, + gamma): + + # Estimate the star quantities -- use one of three methods to + # do this -- the primitive variable Riemann solver, the two + # shock approximation, or the two rarefaction approximation. + # Pick the method based on the pressure states at the + # interface. + + p_max = max(p_l, p_r) + p_min = min(p_l, p_r) + + Q = p_max / p_min + + rho_avg = 0.5 * (rho_l + rho_r) + c_avg = 0.5 * (c_l + c_r) + + # primitive variable Riemann solver (Toro, 9.3) + factor = rho_avg * c_avg + + pstar = 0.5 * (p_l + p_r) + 0.5 * (u_l - u_r) * factor + ustar = 0.5 * (u_l + u_r) + 0.5 * (p_l - p_r) / factor + + if Q > 2 and (pstar < p_min or pstar > p_max): + + # use a more accurate Riemann solver for the estimate here + + if pstar < p_min: + + # 2-rarefaction Riemann solver + z = (gamma - 1.0) / (2.0 * gamma) + p_lr = (p_l / p_r)**z + + ustar = (p_lr * u_l / c_l + u_r / c_r + + 2.0 * (p_lr - 1.0) / (gamma - 1.0)) / \ + (p_lr / c_l + 1.0 / c_r) + + pstar = 0.5 * (p_l * (1.0 + (gamma - 1.0) * (u_l - ustar) / + (2.0 * c_l))**(1.0 / z) + + p_r * (1.0 + (gamma - 1.0) * (ustar - u_r) / + (2.0 * c_r))**(1.0 / z)) + + else: + + # 2-shock Riemann solver + A_r = 2.0 / ((gamma + 1.0) * rho_r) + B_r = p_r * (gamma - 1.0) / (gamma + 1.0) + + A_l = 2.0 / ((gamma + 1.0) * rho_l) + B_l = p_l * (gamma - 1.0) / (gamma + 1.0) + + # guess of the pressure + p_guess = max(0.0, pstar) + + g_l = np.sqrt(A_l / (p_guess + B_l)) + g_r = np.sqrt(A_r / (p_guess + B_r)) + + pstar = (g_l * p_l + g_r * p_r - (u_r - u_l)) / (g_l + g_r) + + ustar = 0.5 * (u_l + u_r) + \ + 0.5 * ((pstar - p_r) * g_r - (pstar - p_l) * g_l) + + # estimate the nonlinear wave speeds + + if pstar <= p_l: + # rarefaction + S_l = u_l - c_l + else: + # shock + S_l = u_l - c_l * np.sqrt(1.0 + ((gamma + 1.0) / (2.0 * gamma)) * + (pstar / p_l - 1.0)) + + if pstar <= p_r: + # rarefaction + S_r = u_r + c_r + else: + # shock + S_r = u_r + c_r * np.sqrt(1.0 + ((gamma + 1.0) / (2.0 / gamma)) * + (pstar / p_r - 1.0)) + + return S_l, S_r + + @njit(cache=True) def riemann_hllc(idir, ng, idens, ixmom, iymom, iener, irhoX, nspec, @@ -683,96 +768,8 @@ def riemann_hllc(idir, ng, c_l = max(smallc, np.sqrt(gamma * p_l / rho_l)) c_r = max(smallc, np.sqrt(gamma * p_r / rho_r)) - # Estimate the star quantities -- use one of three methods to - # do this -- the primitive variable Riemann solver, the two - # shock approximation, or the two rarefaction approximation. - # Pick the method based on the pressure states at the - # interface. - - p_max = max(p_l, p_r) - p_min = min(p_l, p_r) - - Q = p_max / p_min - - rho_avg = 0.5 * (rho_l + rho_r) - c_avg = 0.5 * (c_l + c_r) - - # primitive variable Riemann solver (Toro, 9.3) - factor = rho_avg * c_avg - # factor2 = rho_avg / c_avg - - pstar = 0.5 * (p_l + p_r) + 0.5 * (un_l - un_r) * factor - ustar = 0.5 * (un_l + un_r) + 0.5 * (p_l - p_r) / factor - - # rhostar_l = rho_l + (un_l - ustar) * factor2 - # rhostar_r = rho_r + (ustar - un_r) * factor2 - - if Q > 2 and (pstar < p_min or pstar > p_max): - - # use a more accurate Riemann solver for the estimate here - - if pstar < p_min: - - # 2-rarefaction Riemann solver - z = (gamma - 1.0) / (2.0 * gamma) - p_lr = (p_l / p_r)**z - - ustar = (p_lr * un_l / c_l + un_r / c_r + - 2.0 * (p_lr - 1.0) / (gamma - 1.0)) / \ - (p_lr / c_l + 1.0 / c_r) - - pstar = 0.5 * (p_l * (1.0 + (gamma - 1.0) * (un_l - ustar) / - (2.0 * c_l))**(1.0 / z) + - p_r * (1.0 + (gamma - 1.0) * (ustar - un_r) / - (2.0 * c_r))**(1.0 / z)) - - # rhostar_l = rho_l * (pstar / p_l)**(1.0 / gamma) - # rhostar_r = rho_r * (pstar / p_r)**(1.0 / gamma) - - else: - - # 2-shock Riemann solver - A_r = 2.0 / ((gamma + 1.0) * rho_r) - B_r = p_r * (gamma - 1.0) / (gamma + 1.0) - - A_l = 2.0 / ((gamma + 1.0) * rho_l) - B_l = p_l * (gamma - 1.0) / (gamma + 1.0) - - # guess of the pressure - p_guess = max(0.0, pstar) - - g_l = np.sqrt(A_l / (p_guess + B_l)) - g_r = np.sqrt(A_r / (p_guess + B_r)) - - pstar = (g_l * p_l + g_r * p_r - - (un_r - un_l)) / (g_l + g_r) - - ustar = 0.5 * (un_l + un_r) + \ - 0.5 * ((pstar - p_r) * g_r - (pstar - p_l) * g_l) - - # rhostar_l = rho_l * (pstar / p_l + (gamma - 1.0) / (gamma + 1.0)) / \ - # ((gamma - 1.0) / (gamma + 1.0) * (pstar / p_l) + 1.0) - # - # rhostar_r = rho_r * (pstar / p_r + (gamma - 1.0) / (gamma + 1.0)) / \ - # ((gamma - 1.0) / (gamma + 1.0) * (pstar / p_r) + 1.0) - - # estimate the nonlinear wave speeds - - if pstar <= p_l: - # rarefaction - S_l = un_l - c_l - else: - # shock - S_l = un_l - c_l * np.sqrt(1.0 + ((gamma + 1.0) / (2.0 * gamma)) * - (pstar / p_l - 1.0)) - - if pstar <= p_r: - # rarefaction - S_r = un_r + c_r - else: - # shock - S_r = un_r + c_r * np.sqrt(1.0 + ((gamma + 1.0) / (2.0 / gamma)) * - (pstar / p_r - 1.0)) + S_l, S_r = estimate_wave_speed(rho_l, un_l, p_l, c_l, + rho_r, un_r, p_r, c_r, gamma) # We could just take S_c = u_star as the estimate for the # contact speed, but we can actually do this more accurately @@ -956,34 +953,8 @@ def riemann_hllc_lowspeed(idir, ng, c_l = max(smallc, np.sqrt(gamma * p_l / rho_l)) c_r = max(smallc, np.sqrt(gamma * p_r / rho_r)) - # Estimate the star quantities -- we'll just do the PVRS - # estimate here. - - rho_avg = 0.5 * (rho_l + rho_r) - c_avg = 0.5 * (c_l + c_r) - - # primitive variable Riemann solver (Toro, 9.3) - factor = rho_avg * c_avg - - pstar = 0.5 * (p_l + p_r) + 0.5 * (un_l - un_r) * factor - - # estimate the nonlinear wave speeds - - if pstar <= p_l: - # rarefaction - S_l = un_l - c_l - else: - # shock - S_l = un_l - c_l * np.sqrt(1.0 + ((gamma + 1.0) / (2.0 * gamma)) * - (pstar / p_l - 1.0)) - - if pstar <= p_r: - # rarefaction - S_r = un_r + c_r - else: - # shock - S_r = un_r + c_r * np.sqrt(1.0 + ((gamma + 1.0) / (2.0 / gamma)) * - (pstar / p_r - 1.0)) + S_l, S_r = estimate_wave_speed(rho_l, un_l, p_l, c_l, + rho_r, un_r, p_r, c_r, gamma) # We could just take S_c = u_star as the estimate for the # contact speed, but we can actually do this more accurately @@ -1022,7 +993,6 @@ def riemann_hllc_lowspeed(idir, ng, cs_max = max(c_l, c_r) chi = min(1.0, max(vmag_l, vmag_r) / cs_max) phi = chi * (2.0 - chi) - pstar_lr = 0.5 * (p_l + p_r) + \ 0.5 * phi * (rho_l * (S_l - un_l) * (S_c - un_l) + rho_r * (S_r - un_r) * (S_c - un_r))