Modellgalerie
Electrokinetic Valve
This model presents an example of pressure driven flow and electrophoresis in a 3D micro channel system. Researchers often use a device similar to the one in this model as an electrokinetic sample injector in biochips to obtain well-defined sample volumes of dissociated acids and salts and to transport these volumes. Focusing is obtained through pressure driven flow of the sample and buffer ...
Homogeneous Charge Compression Ignition of Methane
Homogeneous Charge Compression Ignition (HCCI) engines are being considered as an alternative to traditional spark- and compression-ignition engines. As the name implies, a homogeneous fuel/oxidant mixture is auto-ignited by compression with simultaneous combustion occurring throughout the cylinder volume. Combustion temperatures under lean burn operation are relatively low, resulting in low ...
Laminar Static Mixer - new
In static mixers, also called motionless or in-line mixers, a fluid is pumped through a pipe containing stationary blades. This mixing technique is particularly well suited for laminar flow mixing because it generates only small pressure losses in this flow regime. This example studies the flow in a twisted-blade static mixer. It evaluates the mixing performance by calculating the ...
Microchannel Cell - new
This example was originally formulated by Albert Witarsa under Professor Bruce Finlayson’s supervision at the University of Washington in Seattle. It was part of a graduate course in which the assignment consisted of evaluating the potential of patents in the field of microfluidics through mathematical modeling. The model treats an H-micro cell for separation through diffusion. The cell puts ...
Drug Release from a Biomaterial Matrix
In this example, drug-release from a biomaterial matrix to damaged cell tissue is modeled. Specifically, a nerve guide delivers a regenerating drug to damaged nerve ends. The model involves detailed drug release kinetics, with rate expressions handling drug dissociation/association reactions as well as matrix degradation by enzyme catalysis. The enzyme reaction is described by Michaelis-Menten ...
Maxwell-Stefan Diffusion in a Fuel Cell Unit Cell
In concentrated gases and liquids, where the concentrations of species are of the same order of magnitude, there is no obvious solvent-solute relationship. Fick’s law for diffusion accounts only for one-way solute-solvent interactions whereas the Maxwell-Stefan equations account for all interactions of species in a solution. In a system with three components, three pair-wise interactions are ...
Protein Adsorption in Ion-Exchange Column - new
Ion-exchange is a powerful method to separate proteins from solutions and is today readily used in biotechnological and pharmaceutical industry. This model simulates an ion-exchange column for protein adsorption. The fluid phase contains four components: two proteins, solvent, and one salt. The adsorption/desorption kinetics is described by two equilibrium reactions where proteins displace ions ...
Liquid Chromatography
In the simplest terms, High Performance Liquid Chromatography (HPLC) is a separation technology - a process used to separate different chemical species that are in a mixture. And while HPLC is one of many separation technologies available, it is the most prevalent because of its versatility. These systems are most commonly used in the pharmaceutical and biotech industries, in functions as ...
Oscillating Droplet - new
Cemented tungsten carbides are hard metals used in steel cutting tools. They are produced by heating a powder consisting typically of tungsten carbide (WC) grains and cobalt (Co) grains. When the powder is heated, the cobalt melts but the tungsten carbide remains solid. The liquid cobalt glues the tungsten carbide grains together and forces air to flow out of the material. When the medium is ...
Boat Reactor for Low Pressure Chemical Vapor Deposition
Chemical vapor deposition (CVD) is an important step in the process of manufacturing microchips. One of the common applications is the deposition of silicon on wafers at low pressure. Low pressure reactors are used to get a high diffusivity of the gaseous species, which results in a uniform deposition thickness, since the process becomes limited by the deposition kinetics. The goal of this ...
