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.
耗散粒子動力學 是對於具有動態和流變性質的簡單及複雜的流體的一種計算模擬方法，它是一個隨機的模擬技術。首先由Hoogerbrugge和Koelman設計提出，去解決分子動力學（MD）所無法解決的流體的時間和空間尺度問題。之後被Espanol公式化，並做了細微的修改，以保證適當的熱平衡態。
DPD是非格子模型介觀模擬技術，囊括粒子群在連續的空間和間斷的時間中運動。粒子代表整個分子或流體的區域，而不是單個原子的，並且原子的細節被認為與過程無關。粒子自身的自由度被整合，並且有一對簡化的耗散的及無規則的力所取代。以此來保證動量守恆，並且保證正確的流體動力學行為。DPD與傳統的MD模擬方法相比，其主要的優勢在於它允許更大的時間尺度和長度尺度。
作用在DPD粒子 i 上力可以當作是所有其他的粒子 j 對 i 的作用力的總和，分為三種成對的力：
第一項是保守力，第二項是耗散力，第三項是隨機力。
