In this project, numerical analysis of the fluid flow inside the Tesla type microvalve as a type of no – moving – part valve and determination of the optimum number of stages for it have been done. No – moving - part valves are used to convert the non - directional ?ow to directional ?ow in reciprocating micropumps. The most common types of this kind of valves are nozzle - diffuser and Tesla valves. In the present study, different layouts of Tesla type microvalve include one - stage, two - stage, three - stage and four - stage are investigated numerically. The main criterion used for evaluation of valve performance is diodicity. Two – dimensional and steady state computations of the fluid flow have been utilized that reveal a strong dependence of diodicity on Reynolds number in the range common for current micropump designs. As a result, two – stage layout of Tesla type valve is the best option between the studied layouts of this type of valve. A two - stage layout of this valve in valveless micropump besides being compact, has the adaptability of the various functions. Also, the two – stage valve performance is compared with nozzle - diffuser type valve. Comparisons which are performed based on calculation of diodicity in applicable range of Reynolds numbers show the superiority of the Tesla type valve in higher Reynolds number and its weakness in lower Reynolds number. Also, in this thesis, a three - dimensional and unsteady analysis of fluid flow inside the ferrofluidic valveless micropump that has no moving mechanical parts is carried out. The micropump is composed of a chamber, a piston, two no – moving - part valves and two channels which one is at the inlet and the other one is at the outlet. In this micropump, ferrofluid plug is employed as piston and flow actuator. Ferrofluid is oscillated in piston due to the external magnetic field actuation that provides the actuation and pumping of the working fluid. Although ferrofluid plug has contact with the working fluid, but with respect to its special features not mix with it. Permanent magnets which are used as ferrofluid actuators, are moved with stepper motor. The simulation results of the ferrofluidic valveless micropump with the nozzle - diffuser valve show good agreement with the experimental results and linear relation between head and flow rate in micropump is confirmed. Three - dimensional simulation of reciprocating micropump which consists of ferrofluidic actuation and Tesla type valve show that the micropump with Tesla type valve in comparison with micropump with nozzle – diffuser type valve has lower maximum flow rate and self - pumping frequency in whole of range of operating frequency. However, it has higher maxumum head in high operating frequencies. According to the thermodynamic efficiency, nozzle - diffuser type micropump has better efficiency in low operating frequencies and Tesla type micropump has better efficiency in high operating frequencies. Finally, in this thesis, fabrication and assembling of some ferrofluidic micropumps with Tesla type valve have been done. Fabrication procedure is presented in details. Key words :Micropump, Microvalve, Diodicity, Ferrofluid, Three-dimensional simulation.