Non-rectangular Channels Research Articles

Mold Embossing-Based Soft Lithography for Fabrication of Complex Non-rectangular Channels.

This paper demonstrates a simple, flexible, and controllable technique to fabricate complex non-rectangular microchannels through the mold (e.g., balls) embossing-based soft lithography method. The good ductility of aluminum foil ensures the complete replication of the ball morphology, resulting in creation of the microchannels with a perfect circular cross section. By investigating the fabrication parameters such as the gap size and ball diameter, we can precisely control the width and height of the circular microchannel. More importantly, the method can be extended to create more complex channels with a series of cross-sectional shapes or combined channels through replacing the balls to the molds with various cross sections. Finally, the complex non-rectangular channels were designed and utilized to construct microfluidic valves and improve the mixing results of two liquids.

Gate-Opening Criterion for Generating Dam-Break Flow in Non-Rectangular Wet Bed Channels

A sudden dam failure is usually simulated by the rapid removal of a gate in laboratory tests and numerical simulations. The gate-opening time is often determined according to the Lauber and Hager instantaneous collapse criterion (referred to as the Lauber–Hager criterion), which is established for a rectangular open channel with a dry bed. However, this criterion is not suitable for non-rectangular channels or initial wet-bed conditions. In this study, the effect of the gate-opening time on the wave evolution is investigated by using the large eddy simulation (LES) model. The instantaneous dam-break, namely, a dam-break without a gate, is simulated for comparison. A gate-opening criterion for generating dam-break flow in a non-rectangular wet-bed channel is proposed in this study, which can be used as an extension of the Lauber–Hager criterion and provides a more comprehensive and reasonable estimate of the gate opening time.

A remark on finite volume methods for 2D shallow water equations over irregular bottom topography

The 2D shallow water equations are often solved through finite volume (FV) methods in the presence of irregular topography or in non-rectangular channels. The ability of FV schemes to preserve uniform flow conditions under these circumstances is herein analysed as a preliminary condition for more involved applications. The widely used standard Harten-Lax-Van Leer (HLL) and a well-balanced Roe method are considered, along with a scheme from the class of wave propagation methods. The results indicate that, differently from the other solvers, the standard HLL does not preserve the uniform condition. It is therefore suggested to benchmark numerical schemes under this condition to avoid inaccurate hydrodynamic simulations. The analysis of the discretized equations reveals an unbalance of the HLL transversal fluxes in the streamwise momentum equation. Finally, a modification of the HLL scheme, based on the auxiliary variable balance method, is proposed, which strongly improves the scheme performance.

Numerical Simulation of Boundary-Driven Acoustic Streaming in Microfluidic Channels with Circular Cross-Sections.

While acoustic streaming patterns in microfluidic channels with rectangular cross-sections have been widely shown in the literature, boundary-driven streaming fields in non-rectangular channels have not been well studied. In this paper, a two-dimensional numerical model was developed to simulate the boundary-driven streaming fields on cross-sections of cylindrical fluid channels. Firstly, the linear acoustic pressure fields at the resonant frequencies were solved from the Helmholtz equation. Subsequently, the outer boundary-driven streaming fields in the bulk of fluid were modelled while using Nyborg’s limiting velocity method, of which the limiting velocity equations were extended to be applicable for cylindrical surfaces in this work. In particular, acoustic streaming fields in the primary (1, 0) mode were presented. The results are expected to be valuable to the study of basic physical aspects of microparticle acoustophoresis in microfluidic channels with circular cross-sections and the design of acoustofluidic devices for micromanipulation.

Inertial microfluidics: A method for fast prediction of focusing pattern of particles in the cross section of the channel

Inertial microfluidics is utilized as a powerful passive method for particle and cell manipulation, which uses the hydrodynamic forces of the fluid in the channel to focus particles in specific equilibrium positions in the cross section of the channel. To achieve high performance manipulation, knowledge of focusing pattern of particles in the cross section of channel is essential. In this paper, we propose a method to address this important issue. To this end, firstly inertial microfluidics is analyzed in rectangular cross section channels. The results indicate that fluid flow velocity and channel's cross-sectional profiles have great impacts on the forces exerted on particles. Next, these results are utilized to propose a method to predict equilibrium positions in non-rectangular cross section channels through some simple calculations. This method is based on approximating the velocity profile of a non-rectangular cross section channel by utilizing portions of velocity profiles of different rectangular cross section channels. To analyze the method's performance, results obtained from the proposed method are compared with Direct Numerical Simulation (DNS) and experimental studies of seven non-rectangular channels. It is observed that the proposed approach accurately predicts particles trajectories and their equilibrium positions in the cross section of channels.

Asymptotic similarity solutions for particle-driven gravity currents in non-rectangular cross-section channels of power-law form

Abstract We consider a high-Reynolds particle-driven gravity current (GC) propagating in channel above a horizontal boundary. The bottom and the top of the channel are at z = 0 , H and its cross-section is given by − f ( z ) ≤ y ≤ f ( z ) for 0 ≤ z ≤ H , where f ( z ) is a power-law function f ( z ) = z α . We focus attention on the similarity stage of propagation of the current using a shallow-water (SW) model. While it is possible to derive the analytical similarity solutions for the homogeneous GC (for which the density of the current remains constant during the propagation), such similarity-solutions do not exist for the particle-driven GCs. We extend the similarity solutions of homogeneous GC to particle-driven currents by developing an asymptotic expansions and derive approximations of such solutions for channels of typical rectangular, triangular and parabolic forms. Comparison with the numerical solution of the SW equations shows that the leading-order asymptotic results are a good approximation in the domain of expected validity. However, out of bounds of this domain the numerical solutions systematically depart from the first-order asymptotic solutions, suggesting the need to include higher-order terms in the asymptotic series.

Critical regime of gravity currents flowing in non-rectangular channels with density stratification

We present theoretical and experimental analyses of the critical condition where the inertial–buoyancy or viscous–buoyancy regime is preserved in a uniform-density gravity current (which propagates over a horizontal plane) of time-variable volume ${\mathcal{V}}=qt^{\unicode[STIX]{x1D6FF}}$ in a power-law cross-section (with width described by $f(z)=bz^{\unicode[STIX]{x1D6FC}}$, where $z$ is the vertical coordinate, $b$ and $q$ are positive real numbers, and $\unicode[STIX]{x1D6FC}$ and $\unicode[STIX]{x1D6FF}$ are non-negative real numbers) occupied by homogeneous or linearly stratified ambient fluid. The magnitude of the ambient stratification is represented by the parameter $S$, with $S=0$ and $S=1$ describing the homogeneous and maximum stratification cases respectively. Earlier theoretical and experimental results valid for a rectangular cross-section ($\unicode[STIX]{x1D6FC}=0$) and uniform ambient fluid are generalized here to a power-law cross-section and stratified ambient. Novel time scalings, obtained for inertial and viscous regimes, allow a derivation of the critical flow parameter $\unicode[STIX]{x1D6FF}_{c}$ and the corresponding propagation rate as $Kt^{\unicode[STIX]{x1D6FD}_{c}}$ as a function of the problem parameters. Estimates of the transition length between the inertial and viscous regimes are also derived. A series of experiments conducted in a semicircular cross-section ($\unicode[STIX]{x1D6FC}=1/2$) validate the critical values $\unicode[STIX]{x1D6FF}_{c}=2$ and $\unicode[STIX]{x1D6FF}_{c}=9/4$ for the two cases $S=0$ and $1$. The ratio between the inertial and viscous forces is determined by an effective Reynolds number proportional to $q$ at some power. The threshold value of this number, which enables a determination of the regime of the current (inertial–buoyancy or viscous–buoyancy) in critical conditions, is determined experimentally for both $S=0$ and $S=1$. We conclude that a very significant generalization of the insights and results from two-dimensional (rectangular cross-section channel) gravity currents to power-law cross-sections is available.

Size-Dependent Inertial Focusing Position Shift and Particle Separations in Triangular Microchannels.

A recent study of inertial microfluidics within nonrectangular cross-section channels showed that the inertial focusing positions changes with cross-sectional shapes; therefore, the cross-sectional shape can be a useful control parameter for microfluidic particle manipulations. Here, we conducted detail investigation on unique focusing position shift phenomena, which occurs strongly in channels with the cross-sectional shape of the isosceles right triangle. The top focusing positions shift along the channel walls to the direction away from the apex with increasing Reynolds number and decreasing particle size. A larger particle with its center further away from the side walls experiences shear gradient lift toward the apex, which leads to an opposite result with changes of Reynolds and particle size. The focusing position shift and the subsequent stabilization of corner focusing lead to changes in the number of focusing positions, which enables a novel method for microparticle separations with high efficiency (>95%) and resolution (<2 μm). The separation method based on equilibrium focusing; therefore, the operation is simple and no complex separation optimization is needed. Moreover, the separation threshold can be easily modulated with flow rate adjustment. Rare cell separation from blood cell was successfully demonstrated with spiked MCF-7 cells in blood by achieving the yield of ∼95% and the throughput of ∼106 cells/min.

Polydisperse particle-driven gravity currents in non-rectangular cross section channels

We consider a high-Reynolds-number gravity current generated by polydisperse suspension of n types of particles distributed in a fluid of density ρi. Each class of particles in suspension has a different settling velocity. The current propagates along a channel of non-rectangular cross section into an ambient fluid of constant density ρa. The bottom and top of the channel are at z = 0, H, and the cross section is given by the quite general form −f1(z) ≤ y ≤ f2(z) for 0 ≤ z ≤ H. The flow is modeled by the one-layer shallow-water equations obtained for the time-dependent motion. We solve the problem by a finite-difference numerical code to present typical height h, velocity u, and mass fractions of particle (concentrations) (ϕ( j), j = 1, …, n) profiles. The runout length of suspensions in channels of power-law cross sections is analytically predicted using a simplified depth-averaged “box” model. We demonstrate that any degree of polydispersivity adds to the runout length of the currents, relative to that of equivalent monodisperse currents with an average settling velocity. The theoretical predictions are supported by the available experimental data. The present approach is a significant generalization of the particle-driven gravity current problem: on the one hand, now the monodisperse current in non-rectangular channels is a particular case of n = 1. On the other hand, the classical formulation of polydisperse currents for a rectangular channel is now just a particular case, f(z) = const., in the wide domain of cross sections covered by this new model.

Thin-film flow in helically wound shallow channels of arbitrary cross-sectional shape

We consider the steady, gravity-driven flow of a thin film of viscous fluid down a helically wound shallow channel of arbitrary cross-sectional shape with arbitrary torsion and curvature. This extends our previous work [D. J. Arnold et al., “Thin-film flow in helically-wound rectangular channels of arbitrary torsion and curvature,” J. Fluid Mech. 764, 76–94 (2015)] on channels of rectangular cross section. The Navier-Stokes equations are expressed in a novel, non-orthogonal coordinate system fitted to the channel bottom. By assuming that the channel depth is small compared to its width and that the fluid depth in the vertical direction is also small compared to its typical horizontal extent, we are able to solve for the velocity components and pressure analytically. Using these results, a differential equation for the free surface shape is obtained, which must in general be solved numerically. Motivated by the aim of understanding flows in static spiral particle separators used in mineral processing, we investigate the effect of cross-sectional shape on the secondary flow in the channel cross section. We show that the competition between gravity and inertia in non-rectangular channels is qualitatively similar to that in rectangular channels, but that the cross-sectional shape has a strong influence on the breakup of the secondary flow into multiple clockwise-rotating cells. This may be triggered by small changes to the channel geometry, such as one or more bumps in the channel bottom that are small relative to the fluid depth. In contrast to the secondary flow which is quite sensitive to small bumps in the channel bottom, the free-surface profile is relatively insensitive to these. The sensitivity of the flow to the channel geometry may have important implications for the design of efficient spiral particle separators.

Inertial focusing in non-rectangular cross-section microchannels and manipulation of accessible focusing positions.

Inertial focusing in microfluidic channels has been extensively studied experimentally and theoretically, which has led to various applications including microfluidic separation and enrichment of cells. Inertial lift forces are strongly dependent on the flow velocity profile and the channel cross-sectional shape. However, the channel cross-sections studied have been limited to circles and rectangles. We studied inertial focusing in non-rectangular cross-section channels to manipulate the flow profile and thus the inertial focusing of microparticles. The location and number of focusing positions are analyzed with varying cross-sectional shapes and Reynolds number. We found that the broken symmetry of non-equilateral triangular channels leads to the shifting of focusing positions with varying Reynolds number. Non-rectangular channels have unique mapping of the focusing positions and the corresponding basins of attraction. By connecting channels with different cross-sectional shapes, we were able to manipulate the accessible focusing positions and achieve focusing of microparticles to a single stream with ∼99% purity.

Erratum to: Shallow-water solutions for gravity currents in non-rectangular cross-area channels with stratified ambient

We consider the propagation of a high-Reynolds-number gravity current in a horizontal channel along the horizontal coordinate $$x$$ . The current is of constant density, $$\rho _c$$ , and the ambient has a linear stable stratification, from $$\rho _{b}$$ at the bottom $$z=0$$ to $$\rho _{o}$$ at the top $$z=H$$ . The cross-section of the channel is given by the quite general $$-f_1(z)\le y \le f_2(z)$$ for $$0 \le z \le H$$ . We develop a one-layer shallow-water (SW) formulation, and we implement it for the solution of a gravity current of fixed volume released from a lock (we focus on a “heavy” bottom current with $$\rho _{c}\ge \rho _{b}$$ ). The dependent variables are the position of the interface, $$h(x,t)$$ , and the speed (averaged over the area of the current), $$u(x,t)$$ , where $$t$$ is the time. The non-rectangular cross-section geometry enters the formulation via $$f(h)$$ and integrals of $$f(z), z f(z)$$ and $$z^2 f(z)$$ , where $$f(z) = f_1(z) + f_2(z)$$ is the width of the channel. For a given geometry $$f(z)$$ , the free input parameters are (1) the height ratio $$H/h_0$$ of ambient to lock; and (2) the stratification parameter $$S = (\rho _{b}- \rho _{o})/(\rho _{c}- \rho _{o})$$ . In general, the SW equations of motion are a hyperbolic PDE system which we solve by a finite-difference method. However, we show that the initial motion displays a “slumping” stage with constant speed of propagation; this can be calculated exactly by the method of characteristics. An analytical solution for the long-time self-similar propagation is also presented for $$S=1$$ and the power-law $$f(z) = bz^\alpha $$ cross section profile. Solutions are presented for various stratification and typical geometries: power-law ( $$f(z) = b z^\alpha $$ , where $$b, \alpha $$ are positive constants), power-law B ( $$f(z) = b( H-z)^\alpha $$ ), trapezoidal, and circle. In general, the increase of the stratification parameter $$S$$ causes a reduction of the speed of propagation, but the details depend on the geometry of the cross section. We also show that, upon a simple transformation, the solutions for the bottom (“heavy”) current can be used for the prediction of top (“light”) currents The present solution is a significant generalization of the classical analysis of the gravity current in a stratified ambient problem (including the “intrusion” situation when $$S=1$$ ). The classical formulation for a rectangular (or laterally unbounded) channel is now just a particular case, $$f(z) = $$ const., in the wide domain of cross-sections covered by the new model. The present solution is reduced to the non-stratified (homogeneous) ambient counterpart by setting $$S=0$$ . The flow under consideration is relevant to environmental and geophysical applications like ventilation of tunnels and discharges in ducts and rivers.

Gravity currents in non-rectangular cross-section channels: extensions to non-Boussinesq systems

We consider the propagation of a gravity current of density $$\rho _c$$ from a lock length $$x_0$$ and height $$h_0$$ into an ambient fluid of density $$\rho _a$$ in a horizontal channel of height $$H$$ along the horizontal coordinate x. The bottom and top of the channel are at $$z = 0, H$$ , and the cross-section is given by the quite general $$f_{1}(z)\le y \le f_{2}(z)$$ for $$0 \le z \le H$$ . When the Reynolds number is large, the resulting flow is governed by the parameters $$\rho _{c}/\rho _{a}$$ , $$H^{*} = H/h_{0}$$ and $$f(z)=f_{1}(z)+f_{2}(z)$$ . We show that the shallow-water one-layer model, combined with a Benjamin-type front condition, provides a versatile formulation for the thickness $$h$$ and speed $$u$$ of the current. The results cover in a continuous manner the range of light $$\rho _{c}/\rho _{a} \ll 1$$ , Boussinesq $$\rho _{c}/\rho _{a} \approx 1$$ and heavy $$\rho _{c}/\rho _{a} \gg 1$$ currents in a fairly wide range of depth ratio in various cross-section geometries. We obtain analytical solutions for the initial dam-break stage of propagation with constant speed, which appears for any cross-section geometry, and derive explicitly the trend for small and large values of the governing parameters. For large time, $$t$$ , a self-similar propagation is feasible only for heavy currents in channels with $$f(z)=bz^{\alpha }$$ cross-sections or for light currents in channels of $$f(z) = (H-z)^\alpha $$ , with $$t^{(2+2\alpha )/(3+2\alpha )}$$ . The methodology is illustrated for non-Boussinesq flow in typical geometries: power-law ( $$f(z) = z^{\alpha }$$ and $$f(z) = (H-z)^{\alpha }$$ , where $$\alpha $$ is positive constant), trapezoidal and circle (full or sector). The present approach is a significant generalization of the classical non-Boussinesq gravity current problem. The classical formulation for a rectangular (or laterally unbounded) channel is now just a particular case, $$f(z) = const.$$ , in the wide domain of cross-sections covered by this new model.

Shallow-water solutions for gravity currents in non-rectangular cross-area channels with stratified ambient

Shallow-water solutions for gravity currents in non-rectangular cross-area channels with stratified ambient

Two-layer shallow-water dam-break solutions for gravity currents in non-rectangular cross-area channels

AbstractWe consider the propagation of a high-Reynolds-number gravity current in a horizontal channel along the horizontal coordinate $x$. The bottom and top of the channel are at $z= 0, H$, and the cross-section is given by the quite general $- {f}_{1} (z)\leq y\leq {f}_{2} (z)$ for $0\leq z\leq H$. We develop a two-layer shallow-water (SW) formulation, and we implement it for the solution of the dam-break problem. The dependent variables are the position of the interface, $h(x, t)$, and the velocity (averaged over the area of the current), $u(x, t)$. The non-rectangular cross-section geometry enters the formulation via $f(h)$ and integrals of $f(z)$ and $zf(z)$, where $f(z)= {f}_{1} (z)+ {f}_{2} (z)$ is the width of the channel. For a given geometry $f(z)$, the free input parameters of the lock-release problem are: (i) the height ratio $H/ {h}_{0} $ of ambient to lock; and (ii) the density ratio of ‘light’ to ‘heavy’ fluids, $R$. We show that the dam-break problem is amenable to solution by the method of characteristics, but various complications (internal jumps, critical restrictions) appear when the return flow in the ambient is significant; these features are not captured by a one-layer shallow-water model. The role of the non-standard geometry in the detection and calculation of the internal and reflected jumps, and on the dam-break flow field, is elucidated. The methodology is illustrated for Boussinesq flow in typical geometries: power-law ($f(z)= b{z}^{\alpha } $, where $b, \alpha $ are positive constants), trapezoidal and circle (full or sector); we solved for full-depth ($H= 1$) and part-depth ($H\gt 1$) lock-release configurations. The approach seems to work well: in all the tested cases, the solution was obtained with simple mathematical and numerical tools (a Runge–Kutta integrator and a secant-method solver); the insights are compatible with our previous understanding of the problem; and the standard (rectangular) case is recovered in the appropriate limit (i.e. when the side-boundaries of the trapezium cross-section are vertical or far apart). A comparison of the speed of propagation with available experiments is also presented, and the agreement is satisfactory. The present solution is a significant generalization of the classical two-layer gravity–current dam-break problem. The classical formulation for a rectangular (or laterally unbounded) channel is now just a particular case, $f(z)= $ const., in the wide domain of cross-sections covered by the new model.

SPH Modeling of One-Dimensional Nonrectangular and Nonprismatic Channel Flows with Open Boundaries

In this study, the authors solve the shallow water equations (SWE) with smoothed particle hydrodynamics (SPH) for one-dimensional (1D) nonrectangular and nonprismatic channel flows with open boundaries. To date, 1D SPH-SWE has been only developed to simulate rectangular prismatic channel flows with closed and open boundaries. However, for practical hydraulic problems, channel cross sections are not always rectangular and prismatic. A general approach is proposed in this study to extend the engineering application range of 1D SPH-SWE to nonrectangular and nonprismatic channels with open boundaries by introducing the wetted cross-sectional area and the water discharge in SWE and combining the method of specified time interval with the inflow/outflow algorithm. Three benchmark study cases, aiming at testing various steady flow regimes in nonrectangular and nonprismatic channels, are adopted to validate the newly proposed approach. Through the investigation of the convergence analysis and numerical accuracy test of the study cases, the results show that the present SPH-SWE approach is capable to model 1D nonrectangular and nonprismatic channel flows with open boundaries.

Publisher's Note: “Gravity currents in non-rectangular cross-section channels: Analytical and numerical solutions of the one-layer shallow-water model for high-Reynolds-number propagation” [Phys. Fluids 25, 026601 (2013)

First Page

Gravity currents in non-rectangular cross-section channels: Analytical and numerical solutions of the one-layer shallow-water model for high-Reynolds-number propagation

We consider the propagation of a high-Reynolds-number gravity current at the bottom of a horizontal channel along the horizontal coordinate x. The bottom and top of the channel are at z = 0, H, and the cross-section is given by the general −f1(z) ⩽ y ⩽ f2(z) for 0 ⩽ z ⩽ H. We use a one-layer, Boussinesq, shallow-water formulation to solve the time-dependent motion produced by release from rest of a fixed volume of fluid from a lock. The dependent variables are the position of the horizontal interface, h(x, t), and the speed (averaged over the area of the current), u(x, t). The non-rectangular cross-section geometry enters the formulation via f(h) and integrals of f(z) and zf(z), where f(z) = f1(z) + f2(z) is the width of the channel. For a given geometry f(z), the only input parameter in the lock-release problem is the height ratio H/h0 of ambient to lock. In general, the solution is obtained by a finite-difference numerical code. Analytical results are derived for the initial dam-break slumping motion, and for the long-time self-similar phase. The model is illustrated for various cross-section shapes: power-law (f(z) = bzα, where b, α are positive constants), trapezoidal, V-shaped valley, and circle-segment. In addition to the quantitative results, the qualitative similarities and differences between the classical rectangular and the general non-rectangular channel have been elucidated: in the first case there is always an initial “slumping” stage of propagation with speed uN = const., followed by a stage of decreasing speed, then a phase of self-similar behavior during which uN decreases like time to some power. In the non-rectangular cross-section channel, the first two stages appear, but the self-similar phase is attained only when the cross-section shape is given by a power-law. When the cross-section of the channel expands upwards, the speed of propagation is larger, and the decay of speed after the slumping stage is weaker, than in the classical rectangular counterpart. The theoretical results are in good agreement with previously published experimental data, but a sharp comparison is not feasible because the experiments were performed in full-depth-lock configurations where the one-layer model is not expected to be accurate.

Discontinuous Galerkin Method for 1D Shallow Water Flow in Nonrectangular and Nonprismatic Channels

A total variation diminishing Runge-Kutta discontinuous Galerkin finite element method for the solution of one-dimensional (1D) shallow water flow equations for natural channels is presented. The hydrostatic pressure force and the wall pressure force terms are combined to simplify the calculations and prevent unphysical flow attributable to improper treatment of the bottom slope term. The treatment of the combined term that appropriately accounts for the momentum flux is given. HLL and Roe Riemann solvers are assessed for the mass and momentum flux terms. Numerical tests are conducted using prismatic rectangular and nonrectangular channels as well as non prismatic channels and natural channel for dam break, supercritical flow, transcritical flow, and dry-bed problems. Slope limiters based on flow cross section area, water surface, and water depth are evaluated. The tests show that HLL and Roe solvers provide similar accuracy. However, the slope limiter based on flow area provides more accurate solutions f...

Interfacing Three-Dimensional Curved Structures and Cellular Adhesion

Curvature is a fundamental geometric design principle found in an array of biological systems, such as vasculature. Therefore, in studying cellular processes such as adhesion, proliferation and migration, it is important to consider the effects of curved 3D micro-topography as compared to flat 2D substrates, which are far more common. Creating these 3D curved systems requires novel approaches as well. Microfluidic devices would seem to be a good approach for this as they have often been utilized as a platform for studying cell adhesion and migration in vitro. However, the fabrication of curved, non-rectangular channels has been a major challenge to the field of microfluidics due to conventional fabrication methods. To overcome these limitations, we have developed a novel and robust approach using mechanical micromachining in combination with a two-step reverse polymer molding process to fabricate microfluidic channels with circular cross-sectional geometries. Here, we utilize these 3D microfluidic networks to study the effects of curvature on cell adhesion mechanics. Both fibroblast (NIH-3T3) and endothelial (HUVEC) cell lines were cultured within circular cross-section microfluidic channels and on reserve molded cylindrical curved polymers. Cell morphology on these curved versus flat substrates was then characterized via confocal and scanning electron microscopy. Furthermore, the formation of stable focal adhesions and cytoskeletal organization was analyzed by immunofluorescent confocal microscopy. We believe that this approach for fabricating bioinspired microfluidic systems provides a powerful platform for interfacing cellular interactions with curved 3D structures, which could be useful in a variety of fields from vascular biology and immune cell transmigration to cell mechanotransduction and tissue engineering.