Initial commit
This commit is contained in:
redclawsystems
@@ -0,0 +1,478 @@
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//! GPU-accelerated k-epsilon turbulence model
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//!
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//! This module provides CUDA-accelerated implementation of the k-epsilon turbulence model
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//! for RANS simulations, including transport equation solving, production term calculation,
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//! and eddy viscosity computation.
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use super::KEpsilonConstants;
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use crate::kernels::CudaKernelManager;
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use crate::{CfdConfig, CfdError, CfdResult};
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use cudarc::driver::{CudaModule, CudaSlice, LaunchConfig, PushKernelArg};
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use std::sync::Arc;
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/// GPU memory buffers for k-epsilon model
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struct KEpsilonGpuBuffers {
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/// Grid dimensions
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nx: usize,
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ny: usize,
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nz: usize,
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/// Turbulent kinetic energy
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k: CudaSlice<f32>,
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k_old: CudaSlice<f32>,
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/// Dissipation rate
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epsilon: CudaSlice<f32>,
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epsilon_old: CudaSlice<f32>,
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/// Velocity gradients
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dudx: CudaSlice<f32>,
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dudy: CudaSlice<f32>,
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dudz: CudaSlice<f32>,
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dvdx: CudaSlice<f32>,
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dvdy: CudaSlice<f32>,
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dvdz: CudaSlice<f32>,
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dwdx: CudaSlice<f32>,
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dwdy: CudaSlice<f32>,
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dwdz: CudaSlice<f32>,
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/// Production and dissipation terms
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production: CudaSlice<f32>,
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dissipation: CudaSlice<f32>,
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eddy_viscosity: CudaSlice<f32>,
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/// Source terms
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source_k: CudaSlice<f32>,
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source_epsilon: CudaSlice<f32>,
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/// Temporary arrays
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temp1: CudaSlice<f32>,
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temp2: CudaSlice<f32>,
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}
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/// GPU-accelerated k-epsilon turbulence model
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pub struct KEpsilonGpuModel {
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/// GPU kernel manager
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kernel_manager: CudaKernelManager,
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/// Model constants
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constants: KEpsilonConstants,
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/// K-epsilon CUDA module
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k_epsilon_module: Option<Arc<CudaModule>>,
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/// GPU memory buffers
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gpu_buffers: Option<KEpsilonGpuBuffers>,
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}
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impl KEpsilonGpuModel {
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/// Create new k-epsilon GPU model
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pub fn new(config: &CfdConfig) -> CfdResult<Self> {
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let kernel_manager = CudaKernelManager::new(config)?;
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Ok(Self {
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kernel_manager,
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constants: KEpsilonConstants::default(),
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k_epsilon_module: None,
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gpu_buffers: None,
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})
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}
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/// Initialize model with grid dimensions
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pub fn initialize(&mut self, nx: usize, ny: usize, nz: usize) -> CfdResult<()> {
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// Load k-epsilon kernels
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self.load_k_epsilon_kernels()?;
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// Allocate GPU buffers
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self.allocate_gpu_buffers(nx, ny, nz)?;
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Ok(())
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}
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/// Load and compile k-epsilon CUDA kernels
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fn load_k_epsilon_kernels(&mut self) -> CfdResult<()> {
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// In real implementation, would compile or load PTX for k-epsilon kernels
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// For now, load from kernel manager
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self.k_epsilon_module = Some(self.kernel_manager.get_module("k_epsilon_kernels")?);
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Ok(())
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}
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/// Allocate GPU memory buffers
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fn allocate_gpu_buffers(&mut self, nx: usize, ny: usize, nz: usize) -> CfdResult<()> {
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let n = nx * ny * nz;
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let buffers = KEpsilonGpuBuffers {
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nx,
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ny,
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nz,
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k: self.kernel_manager.allocate_f32(n)?,
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k_old: self.kernel_manager.allocate_f32(n)?,
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epsilon: self.kernel_manager.allocate_f32(n)?,
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epsilon_old: self.kernel_manager.allocate_f32(n)?,
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dudx: self.kernel_manager.allocate_f32(n)?,
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dudy: self.kernel_manager.allocate_f32(n)?,
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dudz: self.kernel_manager.allocate_f32(n)?,
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dvdx: self.kernel_manager.allocate_f32(n)?,
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dvdy: self.kernel_manager.allocate_f32(n)?,
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dvdz: self.kernel_manager.allocate_f32(n)?,
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dwdx: self.kernel_manager.allocate_f32(n)?,
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dwdy: self.kernel_manager.allocate_f32(n)?,
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dwdz: self.kernel_manager.allocate_f32(n)?,
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production: self.kernel_manager.allocate_f32(n)?,
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dissipation: self.kernel_manager.allocate_f32(n)?,
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eddy_viscosity: self.kernel_manager.allocate_f32(n)?,
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source_k: self.kernel_manager.allocate_f32(n)?,
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source_epsilon: self.kernel_manager.allocate_f32(n)?,
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temp1: self.kernel_manager.allocate_f32(n)?,
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temp2: self.kernel_manager.allocate_f32(n)?,
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};
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self.gpu_buffers = Some(buffers);
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Ok(())
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}
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/// Set initial conditions for k and epsilon
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pub fn set_initial_conditions(&mut self, k_init: f32, epsilon_init: f32) -> CfdResult<()> {
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let buffers = self
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.gpu_buffers
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.as_mut()
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.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
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// Initialize k and epsilon with uniform values
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let n = buffers.nx * buffers.ny * buffers.nz;
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let k_host = vec![k_init; n];
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let epsilon_host = vec![epsilon_init; n];
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self.kernel_manager
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.stream
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.memcpy_htod(&mut buffers.k, &k_host)
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.map_err(|e| CfdError::gpu_error(&format!("Failed to copy k to GPU: {}", e)))?;
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self.kernel_manager
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.stream
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.memcpy_htod(&mut buffers.epsilon, &epsilon_host)
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.map_err(|e| CfdError::gpu_error(&format!("Failed to copy epsilon to GPU: {}", e)))?;
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self.kernel_manager.synchronize()?;
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Ok(())
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}
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/// GPU-accelerated computation of velocity gradients
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pub fn compute_velocity_gradients(
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&mut self,
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u: &CudaSlice<f32>,
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v: &CudaSlice<f32>,
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w: &CudaSlice<f32>,
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dx: f32,
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dy: f32,
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dz: f32,
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) -> CfdResult<()> {
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let buffers = self
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.gpu_buffers
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.as_mut()
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.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
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let module = self
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.k_epsilon_module
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.as_ref()
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.ok_or_else(|| CfdError::gpu_error("K-epsilon module not loaded"))?;
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let func = module
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.load_function("compute_velocity_gradients")
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.map_err(|e| {
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CfdError::gpu_error(&format!("Failed to get velocity gradients kernel: {}", e))
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})?;
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let grid_dim_x = (buffers.nx as u32 + 7) / 8;
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let grid_dim_y = (buffers.ny as u32 + 7) / 8;
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let grid_dim_z = (buffers.nz as u32 + 7) / 8;
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let config = LaunchConfig {
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grid_dim: (grid_dim_x, grid_dim_y, grid_dim_z),
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block_dim: (8, 8, 8),
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shared_mem_bytes: 0,
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};
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unsafe {
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self.kernel_manager
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.stream()
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.launch_builder(&func)
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.arg(u)
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.arg(v)
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.arg(w)
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.arg(&mut buffers.dudx)
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.arg(&mut buffers.dudy)
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.arg(&mut buffers.dudz)
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.arg(&mut buffers.dvdx)
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.arg(&mut buffers.dvdy)
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.arg(&mut buffers.dvdz)
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.arg(&mut buffers.dwdx)
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.arg(&mut buffers.dwdy)
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.arg(&mut buffers.dwdz)
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.arg(&dx)
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.arg(&dy)
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.arg(&dz)
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.arg(&(buffers.nx as i32))
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.arg(&(buffers.ny as i32))
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.arg(&(buffers.nz as i32))
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.launch(config)
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.map_err(|e| {
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CfdError::gpu_error(&format!("Velocity gradients kernel launch failed: {}", e))
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})?;
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}
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self.kernel_manager.synchronize()?;
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Ok(())
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}
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/// Compute eddy viscosity on GPU
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pub fn compute_eddy_viscosity(&mut self) -> CfdResult<()> {
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let buffers = self
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.gpu_buffers
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.as_mut()
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.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
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let module = self
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.k_epsilon_module
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.as_ref()
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.ok_or_else(|| CfdError::gpu_error("K-epsilon module not loaded"))?;
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let func = module
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.load_function("compute_eddy_viscosity")
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.map_err(|e| {
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CfdError::gpu_error(&format!("Failed to get eddy viscosity kernel: {}", e))
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})?;
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let grid_dim_x = (buffers.nx as u32 + 7) / 8;
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let grid_dim_y = (buffers.ny as u32 + 7) / 8;
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let grid_dim_z = (buffers.nz as u32 + 7) / 8;
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let config = LaunchConfig {
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grid_dim: (grid_dim_x, grid_dim_y, grid_dim_z),
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block_dim: (8, 8, 8),
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shared_mem_bytes: 0,
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};
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unsafe {
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self.kernel_manager
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.stream()
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.launch_builder(&func)
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.arg(&buffers.k)
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.arg(&buffers.epsilon)
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.arg(&mut buffers.eddy_viscosity)
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.arg(&self.constants.c_mu)
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.arg(&(buffers.nx as i32))
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.arg(&(buffers.ny as i32))
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.arg(&(buffers.nz as i32))
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.launch(config)
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.map_err(|e| {
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CfdError::gpu_error(&format!("Eddy viscosity kernel launch failed: {}", e))
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})?;
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}
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self.kernel_manager.synchronize()?;
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Ok(())
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}
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/// Compute production term P_k
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pub fn compute_production(&mut self) -> CfdResult<()> {
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let buffers = self
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.gpu_buffers
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.as_mut()
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.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
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let module = self
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.k_epsilon_module
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.as_ref()
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.ok_or_else(|| CfdError::gpu_error("K-epsilon module not loaded"))?;
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let func = module
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.load_function("compute_production")
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.map_err(|e| CfdError::gpu_error(&format!("Failed to get production kernel: {}", e)))?;
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let grid_dim_x = (buffers.nx as u32 + 7) / 8;
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let grid_dim_y = (buffers.ny as u32 + 7) / 8;
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let grid_dim_z = (buffers.nz as u32 + 7) / 8;
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let config = LaunchConfig {
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grid_dim: (grid_dim_x, grid_dim_y, grid_dim_z),
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block_dim: (8, 8, 8),
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shared_mem_bytes: 0,
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};
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unsafe {
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self.kernel_manager
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.stream()
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.launch_builder(&func)
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.arg(&buffers.eddy_viscosity)
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.arg(&buffers.dudx)
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.arg(&buffers.dudy)
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.arg(&buffers.dudz)
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.arg(&buffers.dvdx)
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.arg(&buffers.dvdy)
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.arg(&buffers.dvdz)
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.arg(&buffers.dwdx)
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.arg(&buffers.dwdy)
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.arg(&buffers.dwdz)
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.arg(&mut buffers.production)
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.arg(&(buffers.nx as i32))
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.arg(&(buffers.ny as i32))
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.arg(&(buffers.nz as i32))
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.launch(config)
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.map_err(|e| {
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CfdError::gpu_error(&format!("Production kernel launch failed: {}", e))
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})?;
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}
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self.kernel_manager.synchronize()?;
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Ok(())
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}
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/// Compute source terms for epsilon equation
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pub fn compute_epsilon_source(&mut self) -> CfdResult<()> {
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let buffers = self
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.gpu_buffers
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.as_mut()
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.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
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let module = self
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.k_epsilon_module
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.as_ref()
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.ok_or_else(|| CfdError::gpu_error("K-epsilon module not loaded"))?;
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let func = module
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.load_function("compute_epsilon_source")
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.map_err(|e| {
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CfdError::gpu_error(&format!("Failed to get epsilon source kernel: {}", e))
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})?;
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let grid_dim_x = (buffers.nx as u32 + 7) / 8;
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let grid_dim_y = (buffers.ny as u32 + 7) / 8;
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let grid_dim_z = (buffers.nz as u32 + 7) / 8;
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let config = LaunchConfig {
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grid_dim: (grid_dim_x, grid_dim_y, grid_dim_z),
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block_dim: (8, 8, 8),
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shared_mem_bytes: 0,
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};
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unsafe {
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self.kernel_manager
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.stream()
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.launch_builder(&func)
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.arg(&buffers.k)
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.arg(&buffers.epsilon)
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.arg(&buffers.production)
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.arg(&mut buffers.source_epsilon)
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.arg(&self.constants.c_e1)
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.arg(&self.constants.c_e2)
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.arg(&(buffers.nx as i32))
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.arg(&(buffers.ny as i32))
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.arg(&(buffers.nz as i32))
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.launch(config)
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.map_err(|e| {
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CfdError::gpu_error(&format!("Epsilon source kernel launch failed: {}", e))
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})?;
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}
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self.kernel_manager.synchronize()?;
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Ok(())
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}
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/// Update k and epsilon using implicit time integration
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pub fn update_k_epsilon(&mut self, dt: f32, nu: f32) -> CfdResult<()> {
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let buffers = self
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.gpu_buffers
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.as_mut()
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.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
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// Store old values
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buffers.k_old = buffers.k.clone();
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buffers.epsilon_old = buffers.epsilon.clone();
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let module = self
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.k_epsilon_module
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.as_ref()
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.ok_or_else(|| CfdError::gpu_error("K-epsilon module not loaded"))?;
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let func = module
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.load_function("update_k_epsilon")
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.map_err(|e| CfdError::gpu_error(&format!("Failed to get update kernel: {}", e)))?;
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let grid_dim_x = (buffers.nx as u32 + 7) / 8;
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let grid_dim_y = (buffers.ny as u32 + 7) / 8;
|
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let grid_dim_z = (buffers.nz as u32 + 7) / 8;
|
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|
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let config = LaunchConfig {
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grid_dim: (grid_dim_x, grid_dim_y, grid_dim_z),
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block_dim: (8, 8, 8),
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shared_mem_bytes: 0,
|
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};
|
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|
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unsafe {
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self.kernel_manager
|
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.stream()
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.launch_builder(&func)
|
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.arg(&mut buffers.k)
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.arg(&mut buffers.epsilon)
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.arg(&buffers.k_old)
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.arg(&buffers.epsilon_old)
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.arg(&buffers.production)
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.arg(&buffers.source_epsilon)
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.arg(&buffers.eddy_viscosity)
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.arg(&dt)
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.arg(&nu)
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.arg(&self.constants.sigma_k)
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.arg(&self.constants.sigma_e)
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.arg(&(buffers.nx as i32))
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.arg(&(buffers.ny as i32))
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.arg(&(buffers.nz as i32))
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.launch(config)
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.map_err(|e| CfdError::gpu_error(&format!("Update kernel launch failed: {}", e)))?;
|
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}
|
||||
|
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self.kernel_manager.synchronize()?;
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Ok(())
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}
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/// Get eddy viscosity field from GPU
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pub fn get_eddy_viscosity(&self) -> CfdResult<Vec<f32>> {
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let buffers = self
|
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.gpu_buffers
|
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.as_ref()
|
||||
.ok_or_else(|| CfdError::gpu_error("GPU buffers not initialized"))?;
|
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|
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let n = buffers.nx * buffers.ny * buffers.nz;
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let mut eddy_viscosity_host = vec![0.0f32; n];
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self.kernel_manager
|
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.stream
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.memcpy_dtoh(&mut eddy_viscosity_host, &buffers.eddy_viscosity)
|
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.map_err(|e| {
|
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CfdError::gpu_error(&format!("Failed to copy eddy viscosity from GPU: {}", e))
|
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})?;
|
||||
|
||||
self.kernel_manager.synchronize()?;
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Ok(eddy_viscosity_host)
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||||
}
|
||||
|
||||
/// Complete time step for k-epsilon model
|
||||
pub fn step(
|
||||
&mut self,
|
||||
u: &CudaSlice<f32>,
|
||||
v: &CudaSlice<f32>,
|
||||
w: &CudaSlice<f32>,
|
||||
dx: f32,
|
||||
dy: f32,
|
||||
dz: f32,
|
||||
dt: f32,
|
||||
nu: f32,
|
||||
) -> CfdResult<()> {
|
||||
// Compute velocity gradients
|
||||
self.compute_velocity_gradients(u, v, w, dx, dy, dz)?;
|
||||
|
||||
// Compute eddy viscosity
|
||||
self.compute_eddy_viscosity()?;
|
||||
|
||||
// Compute production term
|
||||
self.compute_production()?;
|
||||
|
||||
// Compute source terms
|
||||
self.compute_epsilon_source()?;
|
||||
|
||||
// Update k and epsilon
|
||||
self.update_k_epsilon(dt, nu)?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user