A computational analysis and design methodology is presented for effective microflow control using synthetic jets. The membrane is modeled as a moving boundary to accurately compute the flow inside the jet cavity. Compressible Navier-Stokes equations are solved with boundary conditions for the wall slip and the temperature jump conditions encountered for a specific range of Knudsen numbers. For validation, microchannel flow and microfilter flow are successfully computed. Then, flow past a backward-facing step in a microchannel is considered. Analysis is coupled with a design methodology to improve the actuator effectiveness. The objective function is selected to be the square of the vorticity (enstrophy) integrated over a separated region. First, from a design of experiments study, orifice and actuator cavity widths are identified as the most effective design variables. Then, a response surface method is constructed to find the improved control of the flow. This optimization results in more than 83% reduction of the enstrophy of the recirculation region.

With increasing demands in real-time or near real-time remotely sensed imagery applications in such as military deployments, quick response to terrorist attacks and disaster rescue, the on-board geometric calibration problem has attracted the attention of many scientists in recent years. This paper presents an on-board geometric calibration method for linear CCD sensor arrays using FPGA chips. The proposed method mainly consists of four modules—Input Data, Coefficient Calculation, Adjustment Computation and Comparison—in which the parallel computations for building the observation equations and least squares adjustment, are implemented using FPGA chips, for which a decomposed matrix inversion method is presented. A Xilinx Virtex-7 FPGA VC707 chip is selected and the MOMS-2P data used for inflight geometric calibration from DLR (Köln, Germany), are employed for validation and analysis. The experimental results demonstrated that: (1) When the widths of floating-point data from 44-bit to 64-bit are adopted, the FPGA resources, including the utilizations of FF, LUT, memory LUT, I/O and DSP48, are consumed at a fast increasing rate; thus, a 50-bit data width is recommended for FPGA-based geometric calibration. (2) Increasing number of ground control points (GCPs) does not significantly consume the FPGA resources, six GCPs is therefore recommended for geometric calibration. (3) The FPGA-based geometric calibration can reach approximately 24 times faster speed than the PC-based one does. (4) The accuracy from the proposed FPGA-based method is almost similar to the one from the inflight calibration if the calibration model and GCPs number are the same.

Recently, researchers have started working to develop polymerase chain reaction (PCR) devices as a means for point-of-care (POC) applications. Among the requirements are portability, affordability, and performing reliably and quickly. Proposed by the present study is a process to design a convective-PCR (CPCR) device with only a single heater. It is assumed that such a design developed using microfluidics and capillary tube should help make a CPCR to be portable and more economical for POC use. One of the challenges is to achieve steadily the prerequisite three temperature zones with a single heater. It is demonstrated that this can be done with the present methodology. The underlying physics of the convection driving the CPCR function is mathematically modeled, then verified by our experimental results. In search of better designs, the following parameters that affect the CPCR performance are considered: the heater's height, and the diameter, the height, and the wall thickness of the capillary tube. A large design space consisting of design candidates is defined by combining the values within the range of each of these parameters. The results of the corresponding design cases are obtained from our mathematical model, and the performance of each case is evaluated by their deoxyribonucleic acid (DNA) doubling time. The two best CPCR performing reactors are selected and discussed. It is, therefore, demonstrated that the present methodology is capable of enhancing the CPCR reactor performance with a single heater.