tAdded velocity BC to wall integration algorithm - sphere - GPU-based 3D discrete element method algorithm with optional fluid coupling
(HTM) git clone git://src.adamsgaard.dk/sphere
(DIR) Log
(DIR) Files
(DIR) Refs
(DIR) LICENSE
---
(DIR) commit 9d663f08ba7d578b6b49aff96cc10fc066f49228
(DIR) parent ff88ba6c2a4f262e4f784cf7dca32c2302e8c59e
(HTM) Author: Anders Damsgaard <adc@geo.au.dk>
Date: Thu, 30 Aug 2012 11:54:22 +0200
Added velocity BC to wall integration algorithm
Diffstat:
M src/integration.cuh | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
---
(DIR) diff --git a/src/integration.cuh b/src/integration.cuh
t@@ -173,6 +173,8 @@ __global__ void integrateWalls(Float4* dev_w_nx,
// write-after-read, or write-after-write hazards.
Float4 w_nx = dev_w_nx[idx];
Float4 w_mvfd = dev_w_mvfd[idx];
+ int wmode = devC_wmode[idx]; // Wall BC, 0: devs, 1: vel
+ Float acc;
// Find the final sum of forces on wall
w_mvfd.z = 0.0f;
t@@ -182,17 +184,25 @@ __global__ void integrateWalls(Float4* dev_w_nx,
Float dt = devC_dt;
- // Normal load = Deviatoric stress times wall surface area,
- // directed downwards.
- Float N = -w_mvfd.w*devC_L[0]*devC_L[1];
+ // If wall BC is controlled by deviatoric stress:
+ if (wmode == 0) {
- // Calculate resulting acceleration of wall
- // (Wall mass is stored in w component of position Float4)
- Float acc = (w_mvfd.z+N)/w_mvfd.x;
+ // Normal load = Deviatoric stress times wall surface area,
+ // directed downwards.
+ Float N = -w_mvfd.w*devC_L[0]*devC_L[1];
- // Update linear velocity
- w_mvfd.y += acc * dt;
+ // Calculate resulting acceleration of wall
+ // (Wall mass is stored in w component of position Float4)
+ acc = (w_mvfd.z+N)/w_mvfd.x;
+ // Update linear velocity
+ w_mvfd.y += acc * dt;
+
+ // Wall BC is controlled by velocity
+ } else if (wmode == 1) {
+ acc = 0.0f;
+ }
+
// Update position. Second-order scheme based on Taylor expansion
// (greater accuracy than the first-order Euler's scheme)
w_nx.w += w_mvfd.y * dt + (acc * dt*dt)/2.0f;