From 35fa1dc35193d5c016bfb2a72f1cd595dd524e15 Mon Sep 17 00:00:00 2001
From: Matthieu Schaller <matthieu.schaller@durham.ac.uk>
Date: Tue, 9 Feb 2016 21:21:25 +0000
Subject: [PATCH] Smoothing length time derivative computed correctly in the
Gadget-2 case
---
src/hydro/Gadget2/hydro.h | 2 +-
src/hydro/Gadget2/hydro_iact.h | 9 ++++++++-
src/runner.c | 5 +++++
3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/src/hydro/Gadget2/hydro.h b/src/hydro/Gadget2/hydro.h
index 53366bd84d..30d714e253 100644
--- a/src/hydro/Gadget2/hydro.h
+++ b/src/hydro/Gadget2/hydro.h
@@ -203,7 +203,7 @@ __attribute__((always_inline)) INLINE static void hydro_predict_extra(
*/
__attribute__((always_inline))
INLINE static void hydro_end_force(struct part* p) {
-
+
p->entropy_dt *=
(const_hydro_gamma - 1.f) * powf(p->rho, -(const_hydro_gamma - 1.f));
}
diff --git a/src/hydro/Gadget2/hydro_iact.h b/src/hydro/Gadget2/hydro_iact.h
index 31528b63f5..260f78ba0e 100644
--- a/src/hydro/Gadget2/hydro_iact.h
+++ b/src/hydro/Gadget2/hydro_iact.h
@@ -197,7 +197,7 @@ __attribute__((always_inline)) INLINE static void runner_iact_force(
const float r_inv = 1.0f / r;
/* Get some values in local variables. */
- // const float mi = pi->mass;
+ const float mi = pi->mass;
const float mj = pj->mass;
const float rhoi = pi->rho;
const float rhoj = pj->rho;
@@ -280,6 +280,10 @@ __attribute__((always_inline)) INLINE static void runner_iact_force(
pj->a[1] += acc * dx[1];
pj->a[2] += acc * dx[2];
+ /* Get the time derivative for h. */
+ pi->force.h_dt -= mj * dvdr / rhoj * wi_dr;
+ pj->force.h_dt -= mi * dvdr / rhoi * wj_dr;
+
/* Update the signal velocity. */
pi->v_sig = fmaxf(pi->v_sig, v_sig);
pj->v_sig = fmaxf(pj->v_sig, v_sig);
@@ -366,6 +370,9 @@ __attribute__((always_inline)) INLINE static void runner_iact_nonsym_force(
pi->a[1] -= acc * dx[1];
pi->a[2] -= acc * dx[2];
+ /* Get the time derivative for h. */
+ pi->force.h_dt -= mj * dvdr / rhoj * wi_dr;
+
/* Update the signal velocity. */
pi->v_sig = fmaxf(pi->v_sig, v_sig);
diff --git a/src/runner.c b/src/runner.c
index 66c1e02deb..eeee039344 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -851,8 +851,13 @@ void runner_dokick(struct runner *r, struct cell *c, int timer) {
if (is_fixdt || p->t_end <= t_current) {
/* First, finish the force loop */
+ p->force.h_dt *= p->h * 0.333333333f;
+
+ /* And do the same of the extra variable */
hydro_end_force(p);
+ /* Now we are ready to compute the next time-step size */
+
if (is_fixdt) {
/* Now we have a time step, proceed with the kick */
--
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