Dissipative particle dynamics (DPD) is a computational method for simulating dynamical and rheological properties of both simple and complex fluids. It is a stochastic simulation technique, which was initially devised by Hoogerbrugge and Koelman and to tackle hydrodynamic time and space scales beyond those available with molecular dynamics (MD). It was subsequently reformulated and slightly modified by Espanol to ensure the proper thermal equilibrium state.

DPD is an off-lattice mesoscopic simulation technique which involves a set of particles moving in continuous space and discrete time. Particles represent whole molecules or fluid regions, rather than single atoms, and atomistic details are not considered relevant to the processes addressed. The particles’ internal degrees of freedom are then integrated out and replaced by simplified pairwise dissipative and random forces, so as to locally conserve momentum and ensure correct hydrodynamic behaviour. The main advantage of this method is that it gives access to longer time and length scales compared to what is achievable by conventional MD simulations.

The total force acting on a DPD particle i is expressed as a summation over all the other particles, j, of three forces of the pairwise-additive type:

where the first term in the above equation refers to a conservative force, the second to a dissipative force and the third to a random force.

耗散粒子动力学 是对于具有动态和流变性质的简单及复杂的流体的一种计算模拟方法，它是一个随机的模拟技术。首先由Hoogerbrugge和Koelman设计提出，去解决分子动力学（MD）所无法解决的流体的时间和空间尺度问题。之后被Espanol公式化，并做了细微的修改，以保证适当的热平衡态。

DPD是非格子模型介观模拟技术，囊括粒子群在连续的空间和间断的时间中运动。粒子代表整个分子或流体的区域，而不是单个原子的，并且原子的细节被认为与过程无关。粒子自身的自由度被整合，并且有一对简化的耗散的及无规则的力所取代。以此来保证动量守恒，并且保证正确的流体动力学行为。DPD与传统的MD模拟方法相比，其主要的优势在于它允许更大的时间尺度和长度尺度。

作用在DPD粒子 i 上力可以当作是所有其他的粒子 j 对 i 的作用力的总和，分为三种成对的力：

第一项是保守力，第二项是耗散力，第三项是随机力。